A baking structure, baking tool and baking method

Abstract

The present invention belongs to the technical field of baking, and specifically relates to a baking structure, baking tooling and baking method, wherein the baking structure comprises an interference-fitting containing body and a contained body, a tapered directional sliding structure is arranged between the containing body and the contained body, a gas escape structure connected to the interlayer between the containing body and the contained body is arranged on the shoulder of the contained body, the tapered directional sliding structure comprises inclined conical surfaces respectively arranged on the inner hole of the containing body and the outer circle of the contained body and matching with each other, the inclined conical surfaces are arranged inwardly from top to bottom, and the gas escape structure comprises a plurality of exhaust grooves uniformly distributed along the circumference of the shoulder of the contained body, one end of the exhaust groove is located on the inner side of the minimum diameter end of the inner hole of the containing body, and the other end is connected to the outside of the shoulder of the contained body. The present invention can achieve a baking gap of ≤0.03mm through the design of the tapered directional sliding structure, the gas escape structure, the double-sided induction coil and the three-point uniform pressure structure, and can even achieve complete fit without gaps.

Description

Technical Field

[0001] The invention belongs to the technical field of baking and packaging, and in particular relates to a baking and packaging structure, a baking and packaging tool and a baking and packaging method. Background Art

[0002] In the prior art, after the gears and gear shafts are assembled, torque is transmitted through interference fit. During actual assembly, large local gaps or even large overall circumferential gaps often occur at the shoulder positions where the enclosing body and the enclosed body fit together. Large gaps will cause axial movement, and uneven gaps will cause axial tilting of the enclosing body and the enclosed body. Axial movement and axial tilting will affect gear meshing, cause unbalanced load problems, and reduce the fatigue life of gear parts.

[0003] The reasons for the large gap mentioned above include manufacturing factors such as poor assembly accuracy or shoulder size interference. One reason is that the hardness of the raw material itself, such as material segregation, leads to differences in elastic modulus, and the inevitable cooling rate differences in the cooling process lead to differences in the micro-area scale of the assembly gap. The other reason is that during the cooling process, the edge cooling rate is fast, and a relatively closed air and water vapor interlayer is formed in the middle of the mating surface. During the continuous cooling process, the interlayer gas is continuously contracted and squeezed by the inclusion body, thereby generating huge air pressure. The air pressure must be released during the contraction process, and finally the interlayer gas exerts huge pressure on the shoulder of the included body, resulting in a gap at the shoulder position. Summary of the invention

[0004] The purpose of the present invention is to solve the problem of large assembly gap between an enclosing body and an enclosed body in the prior art, and to provide a baking structure, baking tool and baking method.

[0005] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a baking structure, including an enclosing body and an enclosed body with interference fit, a tapered directional sliding structure is provided between the enclosing body and the enclosed body, and a gas escape structure connected to the interlayer between the enclosing body and the enclosed body is provided on the shoulder of the enclosed body.

[0006] Preferably, the tapered directional sliding structure comprises inclined conical surfaces which are respectively arranged on the inner hole of the containing body and the outer circle of the contained body and cooperate with each other.

[0007] Preferably, the inclined conical surface is inclined inward from top to bottom, that is, the diameter of the inner hole of the contained body decreases gradually along the direction toward the axial shoulder of the contained body.

[0008] Preferably, the angle between the inclined conical surface and the vertical surface is less than 5°.

[0009] Preferably, the gas escape structure comprises a plurality of exhaust grooves evenly distributed along the circumference of the shoulder of the contained body, one end of the exhaust groove is located on the inner side of the smallest diameter end of the inner hole of the contained body, and the other end is connected to the outside of the shoulder of the contained body.

[0010] Preferably, the enclosure is provided with an induction coil for heating the enclosure, and two induction coils are provided and symmetrically distributed at the upper and lower ends of the inner hole of the enclosure.

[0011] A baking tool comprises the above-mentioned baking structure, a screw rod coaxially connected to the enclosed body, and a three-point support sleeve coaxially connected to the enclosed body, wherein the screw rod passes through the center hole of the three-point support sleeve, and a hollow jack is provided between the screw rod and the three-point support sleeve, and the three-point support sleeve can move in the opposite direction to the screw rod under the action of the hollow jack.

[0012] A baking method for a baking structure comprises the following steps:

[0013] (a) Wipe the baking racks of the inclusion body and the included body clean with alcohol to remove burrs and flanges;

[0014] (b) Calculate the heating temperature of the enclosing body and the freezing temperature of the enclosed body using the following formula:

[0015] 2*tanβ*L+interference<enlargement of the containing body (φx*△T1*a1)+contraction of the contained body (φy*△T2*a2);

[0016] Among them, β is the taper angle of the inclined cone, L is the width of the assembly file, that is, the height of the inner hole of the inclusion body, φx is the small end diameter of the inner hole of the baking file of the inclusion body, △T1 is the heating temperature rise of the inclusion body, φy is the large end diameter of the outer circle of the baking file of the inclusion body, △T2 is the freezing temperature drop of the inclusion body, a1 is the linear expansion coefficient of the inclusion body, and a2 is the linear expansion coefficient of the inclusion body;

[0017] (c) heating the inclusion body to a target temperature and freezing the inclusion body to a target temperature;

[0018] (d) Check the size of the inclusion body and the contained body. The diameter of the small end of the inclusion body should be larger than the diameter of the large end of the contained body by 0.2 mm or more.

[0019] (e) Assemble the enclosing body and the enclosed body coaxially and place them on a baking fixture. Apply pressure through the baking fixture to make the shoulder gap between the enclosing body and the enclosed body zero. After cooling under pressure, remove the baking fixture.

[0020] Preferably, in step (c), double-sided induction coils are used to induction heat the baking stage of the enclosure, and the heating temperature is △T1+room temperature. After heating, a saddle-shaped structure is formed in the baking stage of the enclosure, and the freezing temperature of the enclosure is room temperature-△T1.

[0021] Preferably, in step (e), the pressurization range of the baking tool is 30-40 MPa, and the temperature of the pressure-maintaining cooling is 50° C. or below.

[0022] After adopting the above technical solution, the present invention provides a baking structure, baking tool and baking method, which have the following beneficial effects:

[0023] 1) The present invention adopts the design of the tapered directional sliding structure, and the matching surface with a certain tapered angle and the huge elastic contraction force exert pressure on the assembly surface of the contained body, and the pressure is decomposed. The axial driving force increases the tendency of the contained body to automatically slide toward the shoulder. In the absence of axial external force, the tapered matching surface with an angle less than 5° will produce a self-locking effect, that is, the sliding force of the baking matching surface generated by the pressure decomposition of the cooling and shrinkage of the contained body is less than the friction force of the matching surface; when the jack applies an axial external force, the axial decomposition force exceeds the self-locking friction force of the baking gear, and the contained body will produce a directional sliding toward the shoulder at this time; because the diameter of the contained body tending to the shoulder is getting smaller and smaller, the inverted cone structure produces a directional axial displacement, and will not be driven by the interlayer gas pressure during the cooling process to produce a reverse movement away from the shoulder, and finally achieve the effect of completely fitting the shoulder;

[0024] 2) The present invention, through the design of the gas escape structure, evenly distributes multiple exhaust grooves on the contact surface between the shaft shoulder and the enclosing body, providing an escape channel for the gas in the interlayer during the baking and pressing process; when the temperature of the enclosed body is lower than the dew point temperature of air with a certain water content due to the freezing treatment, the water molecules in the air condense into dewdrops or ice crystal structures, and the condensed water generates water vapor when heated and diffuses in the interlayer. In the conventional assembly process, after the jack is pressed, due to the influence of the incomplete escape of the interlayer gas, it is easy to cause the baking gear with no directional sliding structure to produce reverse sliding, that is, the enclosing body and the enclosed body are fitted without gap in the early cooling stage, and the enclosing body is away from the shaft shoulder in the later stage to form a rebound model with a gap. Therefore, the present invention can avoid this problem;

[0025] 3) The conventional baking heating process is to heat the inclusion body, which produces linear expansion in the diameter direction of the assembly file. For some assembly files with large interference, the overall heating temperature of the inclusion body needs to be 200℃ or above. This temperature is the low-temperature tempering temperature after conventional inclusion carburizing and quenching, which easily leads to a decrease in the hardness of the carburized layer of the inclusion body; and because the assembly file is inevitably cooled quickly on both sides during the cooling process after assembly, and the heat storage in the middle is large and the cooling is slow, the cooling difference will cause the assembly surface of the inclusion body to produce a waist drum-shaped structure, which is not conducive to the overflow of the gas interlayer on the assembly surface. Therefore, the present invention adopts double-sided induction coil heating, and heats both sides of the assembly hole of the inclusion body through two induction coils. The temperature on both sides is higher than the middle part of the assembly hole. In this way, after induction heating, a saddle-shaped structure is produced in the assembly hole of the inclusion body, which can offset the relatively large shrinkage on both sides during assembly cooling; at the same time, the non-carburized surface of the inclusion assembly file, which is low-carbon alloy steel, can be heated to 300℃ by induction heating to increase the expansion of the inclusion body without reducing the hardness of the assembly file; the inclusion body is frozen, and the appropriate freezing temperature can be selected according to the interference of the assembly file;

[0026] 4) The present invention calculates the heating temperature of the enclosing body and the freezing temperature of the enclosing body by the formula 2*tanβ*L+interference amount<enclosing body expansion amount (φx*△T1*a1)+enclosed body contraction amount (φy*△T2*a2), which can ensure that the small end of the enclosing body taper can smoothly enter the assembly gear;

[0027] 5) The present invention adopts a three-point uniform pressure structure through the design of the baking tooling, which can avoid the problems of tilting and overturning of the enclosure and deformation due to uneven force, thereby ensuring the baking effect.

[0028] In summary, by adopting the baking structure, baking tool and baking method provided by the present invention, a baking gap of ≤0.03 mm can be achieved, and even a complete fit without gap can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a structural schematic diagram of a baking structure of the present invention;

[0030] Figure 2 It is a structural schematic diagram of the induction coil in the present invention;

[0031] Figure 3 The figure is a schematic diagram of the assembly structure of a baking structure and baking tooling according to the present invention.

[0032] Among them: an enclosing body 1, an enclosed body 2, an inclined cone surface 3, an exhaust groove 4, an induction coil 5, a screw 6, a three-point support sleeve 7, and a hollow jack 8. DETAILED DESCRIPTION

[0033] The present invention is further described clearly and completely below in conjunction with the accompanying drawings and specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0035] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, numerical expressions and numerical values ​​do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be regarded as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0036] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the devices or elements referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention. The directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0037] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0038] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0039] like Figure 1As shown, a baking structure provided by the present invention comprises an inclusion body 1 and an included body 2 with interference fit, a tapered directional sliding structure is arranged between the inclusion body 1 and the included body 2, the tapered directional sliding structure comprises inclined conical surfaces 3 respectively arranged on the inner hole of the inclusion body 1 and the outer circle of the included body 2 and matching with each other, the inclined conical surfaces 3 are arranged to be inclined inward from top to bottom, that is, the diameter of the inner hole of the inclusion body 1 gradually decreases along the direction toward the shoulder of the included body 2, and preferably, the angle between the inclined conical surface 3 and the vertical plane is less than 5°.

[0040] A gas escape structure connected to the interlayer between the enclosing body 1 and the enclosed body 2 is provided on the shoulder of the enclosed body 2, and the gas escape structure includes a plurality of exhaust grooves 4 evenly distributed along the circumference of the shoulder of the enclosed body 2, preferably 8 exhaust grooves, one end of the exhaust groove 4 is located on the inner side of the smallest diameter end of the inner hole of the enclosing body 1, and the other end is connected to the outside of the shoulder of the enclosed body 2.

[0041] like Figure 2 As shown, the enclosure 1 is provided with an induction coil 5 for heating the enclosure 1 , and two induction coils 5 are provided, which are symmetrically distributed at the upper and lower ends of the inner hole of the enclosure 1 .

[0042] like Figure 3 As shown, a baking tool provided by the present invention includes the above-mentioned baking structure, a screw rod 6 coaxially connected to the enclosed body 2, and a three-point support sleeve 7 coaxially connected to the enclosing body 1, one end of the screw rod 6 is connected to the end of the enclosed body 2, and the other end extends out of the end of the three-point support sleeve 7 away from the enclosing body 1, and the end is provided with a high-strength steel plate with a through hole, the through hole is concentrically arranged with the three-point support sleeve 7, the screw rod 6 passes through the through hole, a hollow jack 8 is provided above the high-strength steel plate with a through hole, the screw rod 6 passes through the hollow jack 8 and a nut is provided between the screw rod 6 and the hollow jack 8, and the three-point support sleeve 7 can move in the opposite direction to the screw rod 6 under the action of the hollow jack 8.

[0043] The present invention provides a baking method for the above-mentioned baking structure, comprising the following steps:

[0044] (a) Wipe the baking racks of the inclusion body and the included body clean with alcohol to remove burrs and flanges;

[0045] (b) Calculate the heating temperature of the enclosing body and the freezing temperature of the enclosed body using the following formula:

[0046] 2*tanβ*L+interference<enlargement of the containing body (φx*△T1*a1)+contraction of the contained body (φy*△T2*a2);

[0047] Among them, β is the taper angle of the inclined cone, L is the width of the assembly file, that is, the height of the inner hole of the inclusion body, φx is the small end diameter of the inner hole of the baking file of the inclusion body, △T1 is the heating temperature rise of the inclusion body, φy is the large end diameter of the outer circle of the baking file of the inclusion body, △T2 is the freezing temperature drop of the inclusion body, a1 is the linear expansion coefficient of the inclusion body, and a2 is the linear expansion coefficient of the inclusion body;

[0048] (c) using double-sided induction coils to heat the inclusion body at the baking stage, the heating temperature is △T1+room temperature, and after a period of time, the infrared thermometer detects the required temperature. After heating, a saddle-shaped structure is formed at the baking stage of the inclusion body, and the inclusion body is frozen, the freezing temperature is room temperature-△T1, and after a period of time, the infrared thermometer detects the required temperature;

[0049] (d) Check the size of the inclusion body and the contained body. The diameter of the small end of the inclusion body should be larger than the diameter of the large end of the contained body by 0.2 mm or more.

[0050] (e) Assemble the enclosing body and the enclosed body coaxially and place them on the drying tooling, start the hollow jack, and continuously increase the pressure to 30-40Mpa, which exceeds the friction force of the tapered directional sliding structure. Under the combined action of the axial decomposition driving force and the pressure of the hollow jack, the enclosing body slides directionally toward the shoulder of the enclosed body until the gap between the shoulders of the enclosing body and the enclosed body is zero. The hollow jack continues to maintain the pressure at 30-40Mpa. After the workpiece cools to 50℃ or below, the drying tooling and the hollow jack can be removed.

[0051] In summary, the baking structure, baking tooling and baking method provided by the present invention can achieve a baking gap of ≤0.03mm, and even achieve complete fitting without gaps, through the design of a tapered directional sliding structure, a gas escape structure, a double-sided induction coil and a three-point uniform pressure structure.

[0052] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A baking structure, characterized in that: The invention comprises an enclosing body (1) and an enclosed body (2) with an interference fit, wherein a tapered directional sliding structure is arranged between the enclosing body (1) and the enclosed body (2), and a gas escape structure is arranged on the shoulder of the enclosed body (2) and is connected to the interlayer between the enclosing body (1) and the enclosed body (2). The tapered directional sliding structure comprises inclined conical surfaces (3) respectively arranged on the inner hole of the enclosing body (1) and the outer circle of the enclosed body (2) and matching with each other, wherein the inclined conical surfaces (3) on the enclosed body (2) are arranged inwardly inclined from top to bottom, that is, the diameter of the inner hole of the enclosing body (1) gradually decreases along the direction toward the shoulder of the enclosed body (2), and the gas escape structure comprises a plurality of exhaust grooves (4) uniformly distributed along the circumference of the shoulder of the enclosed body (2), wherein one end of the exhaust groove (4) is located on the inner side of the smallest diameter end of the inner hole of the enclosing body (1), and the other end is connected to the outside of the shoulder of the enclosed body (2).

2. A drying structure according to claim 1, characterized in that: The angle between the inclined conical surface (3) and the vertical surface is less than 5°.

3. A drying structure according to claim 1, characterized in that: The enclosure (1) is provided with an induction coil (5) for heating the enclosure, and two induction coils (5) are provided and are symmetrically distributed at the upper and lower ends of the inner hole of the enclosure (1).

4. A drying tool, characterized in that: It comprises the baking structure as described in any one of claims 1 to 3, a screw (6) coaxially connected to the contained body (2), and a three-point support sleeve (7) coaxially connected to the containing body (1), wherein the screw (6) passes through the central hole of the three-point support sleeve (7), and a hollow jack (8) is provided between the screw (6) and the three-point support sleeve (7), and the three-point support sleeve (7) can move in the opposite direction to the screw (6) under the action of the hollow jack (8).

5. The baking method of the baking structure according to any one of claims 1 to 3, characterized in that: The following steps are involved: (a) Wipe the baking section of the inclusion body and the inclusion body clean with alcohol to remove burrs and flanges; (b) Calculate the heating temperature of the enclosing body and the freezing temperature of the enclosed body using the following formula: 2×tanβ×L+interference<enlargement of the contained body (φx×△T1×a1)+contraction of the contained body (φy×△T2×a2); Among them, β is the taper angle of the inclined cone, L is the width of the assembly section, that is, the height of the inner hole of the inclusion body, φx is the diameter of the small end of the inner hole of the baking section of the inclusion body, △T1 is the heating temperature rise of the inclusion body, φy is the diameter of the large end of the outer circle of the baking section of the inclusion body, △T2 is the freezing temperature drop of the inclusion body, a1 is the linear expansion coefficient of the inclusion body, and a2 is the linear expansion coefficient of the inclusion body; (c) heating the inclusion body baking section to the target temperature and freezing the inclusion body to the target temperature; (d) Check the size of the inclusion body and the contained body. The diameter of the small end of the inclusion body baking section must be larger than the diameter of the large end of the contained body by 0.2 mm or more; (e) Assemble the enclosing body and the enclosed body coaxially and place them on a baking fixture. Apply pressure through the baking fixture to make the shoulder gap between the enclosing body and the enclosed body zero. After cooling under pressure, remove the baking fixture.

6. A baking method according to claim 5, characterized in that: In the step (c), double-sided induction coils are used to induction heat the baking section of the enclosure, and the heating temperature is ΔT1+room temperature. After heating, a saddle-shaped structure is formed in the baking section of the enclosure, and the freezing temperature of the enclosure is room temperature-ΔT1.

7. A baking method according to claim 5, characterized in that: In the step (e), the pressurization range of the baking tool is 30-40Mpa, and the temperature of the pressure-maintaining cooling is 50°C or below.

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