Manufacturing method of arched eccentric bushing

Abstract

The invention discloses a manufacturing method of an arched eccentric bushing, which comprises the following steps: a forming step: adding powder into a cavity of a mold, and pressing the powder in the cavity by the mold to form an arched eccentric bushing blank; the die comprises a lower punching die, a main core rod, a female die and an upper punching die, a cavity is formed among the top end of the lower punching die, the outer circumferential face of the main core rod, the inner circumferential face of the female die and the bottom end of the upper punching die, one side face of the main core rod is provided with an arch-shaped face forming part, and the arch-shaped face forming part is in a concave shape with the middle being concave and the two sides being flat in the length direction of the main core rod. Sintering: heating and preserving heat of the arched eccentric bushing blank obtained in the forming step in protective gas to sinter the arched eccentric bushing blank; and a heat treatment step: carrying out heat treatment on the arched eccentric bushing blank. According to the manufacturing method of the arched eccentric bushing, the arched eccentric bushing with the convex middle and the two flat edges on one side of the inner hole can be directly formed, so that surface contact on one side of the eccentric bushing is changed into point contact, and the rotating effect of the eccentric bushing is improved.

Description

Technical Field

[0001] The invention relates to the technical field of eccentric sleeve manufacturing, and in particular to a manufacturing method of an arched eccentric sleeve. Background Art

[0002] The eccentric sleeve is a compressor part used for transmitting eccentric motion.

[0003] Structurally, the eccentric sleeve is cylindrical in shape with a polygonal inner hole running through both ends. The conventional eccentric sleeve rotates through the surface contact of the inner hole.

[0004] However, the existing eccentric sleeve has a large contact surface and excessive flatness, which will affect assembly and rotation. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a method for manufacturing an arched eccentric sleeve, which can directly form an arched eccentric sleeve with a convex middle on one side of the inner hole and flat on both sides, so that the surface contact on one side of the eccentric sleeve is changed to point contact, thereby improving the rotation effect of the eccentric sleeve.

[0006] According to an embodiment of the present invention, a manufacturing method of an arched eccentric sleeve is used to form an arched eccentric sleeve with a convex middle and flat sides on one side of an inner hole, the outer shape of the arched eccentric sleeve is cylindrical, the arched eccentric sleeve has a polygonal inner hole passing through both ends, and one side surface of the polygonal inner hole is an arched surface with a convex middle and flat sides along the axial direction of the arched eccentric sleeve, and the manufacturing method comprises the following steps: Forming step: adding powder into a mold cavity, and the mold presses the powder in the mold cavity to form an arched eccentric sleeve blank; The mold comprises a lower punch, a main core rod, a female die and an upper punch, wherein the lower punch is sleeved outside the main core rod, the female die is sleeved outside the lower punch, the upper punch is located above the lower punch, and the cavity is formed between the top of the lower punch, the outer peripheral surface of the main core rod, the inner peripheral surface of the female die and the bottom end of the upper punch, and one side of the main core rod has an arched surface forming portion, and the arched surface forming portion is concave in the middle and flat on both sides along the length direction of the main core rod; Sintering step: heating and keeping the arched eccentric sleeve blank obtained in the forming step in a protective gas for sintering; Heat treatment step: heat treat the arched eccentric sleeve blank.

[0007] A method for manufacturing an arched eccentric sleeve according to an embodiment of the present invention has at least the following beneficial effects: 1. The present invention manufactures an arched eccentric sleeve with a convex middle and flat sides on one side of a formed inner hole. The outer shape of the arched eccentric sleeve is cylindrical. The arched eccentric sleeve has a polygonal inner hole passing through both ends. One side surface of the polygonal inner hole is an arched surface with a convex middle and flat sides along the axial direction of the arched eccentric sleeve. Therefore, the surface contact on one side of the eccentric sleeve is changed to point contact, thereby improving the rotation effect of the eccentric sleeve. At the same time, the surface contact used to fix the transmission position of the eccentric sleeve is changed to point contact, thereby reducing the area of ​​the support position used to fix the transmission position of the eccentric sleeve, making it easier to control the size of the eccentric sleeve during production, ensuring that there is not much difference in the wear and performance of the eccentric sleeves produced in batches, and ensuring the consistency of the quality of batch production.

[0008] 2. The present invention sets a forming step, in which powder is added into a cavity of a mold, and the mold presses the powder in the cavity to form an arched eccentric sleeve blank; the mold comprises a lower punch, a main core rod, a female mold and an upper punch, the lower punch is sleeved outside the main core rod, the female mold is sleeved outside the lower punch, and the upper punch is located above the lower punch, a cavity is formed between the top of the lower punch, the outer peripheral surface of the main core rod, the inner peripheral surface of the female mold and the bottom end of the upper punch, and one side of the main core rod has an arched surface forming portion, and the arched surface forming portion is concave in the middle and flat on both sides along the length direction of the main core rod. It can be understood that the arched surface forming portion is set on one side of the main core rod, so that the forming step can form the arched eccentric sleeve as a whole through the mold, eliminating the need to press and form the blank of the arched eccentric sleeve and then form the arched surface through machining, thereby improving the production efficiency of the arched eccentric sleeve and the consistency of the quality of the produced arched eccentric sleeve.

[0009] 3. The present invention provides a sintering step, in which the arched eccentric sleeve blank obtained in the forming step is heated and kept warm in a protective gas for sintering. Thus, during the sintering process, the bonding force between the powder particles is enhanced to form a strong metal body.

[0010] 4. The present invention provides a heat treatment step, in which the arched eccentric sleeve blank is heat treated, thereby improving the hardness of the arched eccentric sleeve.

[0011] According to a method for manufacturing an arched eccentric sleeve according to an embodiment of the present invention, in the molding step, it includes powder loading action, pressing action and demolding action in sequence. In the powder loading action, the lower punch is stationary, the main core rod and the top surface of the female mold are flush and higher than the top surface of the lower punch, and then the powder is loaded into the cavity. In the pressing action, the upper punch is inserted downward into the female mold to extrude the powder in the cavity to form. In the demolding action, the lower punch is stationary, the upper punch is separated from the female mold upward, and the female mold is separated from the arched eccentric sleeve blank downward, and then the arched eccentric sleeve blank is clamped with a clamp, and the main core rod is then separated from the polygonal inner hole of the arched eccentric sleeve downward.

[0012] Advantageously, the present invention keeps the lower punch stationary during the powder filling operation, and the top surfaces of the main core rod and the female die are flush and higher than the top surface of the lower punch. Then, powder is filled into the cavity, so that the gap between the main core rod, the female die and the top surfaces of the lower punch forms a cavity. During the pressing operation, the upper punch is inserted downward into the female die to extrude the powder in the cavity, so that the upper punch can be inserted into the cavity, so that the upper punch, the main core rod, the female die and the lower punch cooperate to extrude the powder in the cavity. During the demolding operation, the lower punch is stationary, and the upper punch is demolded upward. The female mold is separated from the arched eccentric sleeve blank downward, and then the arched eccentric sleeve blank is clamped with a clip, and the main core rod is separated from the polygonal inner hole of the arched eccentric sleeve downward. It can be understood that when demolding, the female mold is first separated from the arched eccentric sleeve blank downward, so that the outer contour of the arched eccentric sleeve blank is first separated from the restraint of the female mold. At this time, the inner contour of the arched eccentric sleeve is still supported by the main core rod, so that the outer contour of the arched eccentric sleeve blank will not affect the inner contour size of the arched eccentric sleeve when it is demolded and rebounded, thereby avoiding the arched eccentric sleeve blank. The outer contour affects the inner contour size of the arched eccentric sleeve blank during demoulding and rebounding, thereby reducing the factors affecting the inner contour size of the arched eccentric sleeve blank during demoulding, making the inner contour size of the arched eccentric sleeve blank more stable, and making the size of the arched surface of the pressed arched eccentric sleeve more accurate. After the female mold is separated from the arched eccentric sleeve blank, the arched eccentric sleeve blank is clamped with a clamp, and then the main core rod is downwardly separated from the polygonal inner hole of the arched eccentric sleeve blank, so that the clamp can clamp the arched eccentric sleeve blank when the main core rod is demoulded. The core sleeve blank makes the arched eccentric sleeve more stable, so that the main core rod can be demoulded smoothly from the polygonal inner hole of the arched eccentric sleeve blank. When the main core rod is demoulded, the arched surface of the arched eccentric sleeve is squeezed by the main core rod when the main core rod moves, and can rebound and recover after demoulding by utilizing the demoulding rebound characteristics. Since only the inner contour of the arched eccentric sleeve blank rebounds when the main core rod is demoulded, there are fewer factors affecting the inner contour size of the arched eccentric sleeve blank, thereby making the size of the arched surface of the formed arched eccentric sleeve accessories more stable.

[0013] According to a method for manufacturing an arched eccentric sleeve according to an embodiment of the present invention, the maximum arch height of the arched surface is 0.03 0.02mm, the maximum concave depth of the arched surface forming part is 0.045 0.003mm.

[0014] Advantageously, the present invention sets the maximum arch height of the arched surface to 0.03 0.02mm, so that the maximum arch height of the arch surface is relatively small, which facilitates the demoulding of the main core rod in the forming step. At the same time, the maximum concave depth of the arch surface forming part is 0.045 0.003mm. It can be understood that after the arch surface is formed, the arch surface will be squeezed by the main core rod when the main core rod is demolded. After demolding, the arch surface will recover its size by rebounding, but the rebounded size will be smaller than the formed size, so that the maximum concave depth design of the arch surface forming part is controlled within the upper difference range of the maximum arch height of the arch surface, so that the size of the arch surface formed can compensate for the size of the arch surface that is squeezed by the main core rod and rebounded when the main core rod is demolded, thereby making the size of the arch surface recovered by rebound after the main core rod is demolded can be within the size range of the designed maximum arch height of the arch surface.

[0015] According to a method for manufacturing an arched eccentric sleeve according to an embodiment of the present invention, the main core rod is further provided with a stripping slope, and the stripping slope is located on a side of the arched surface forming portion close to the upper punch die.

[0016] The benefit is that: the present invention provides a material withdrawal slope on the main core rod, and the material withdrawal slope is located on the side of the arch surface forming part close to the upper punch die. Therefore, when the main core rod is demolded, the arch surface of the arched eccentric sleeve blank can immediately enter the material withdrawal slope of the main core rod after leaving the arch surface forming part of the main core rod, and then, the arch surface of the arched eccentric sleeve blank can rebound on the material withdrawal slope to restore the arch shape of the arch surface, thereby avoiding the main core rod squeezing the arch surface of the arched eccentric sleeve blank for a long time, which makes the arch surface unable to restore the arch shape through demolding rebound.

[0017] According to a method for manufacturing an arched eccentric sleeve according to an embodiment of the present invention, a transition fillet is provided between the arched surface forming portion and the material withdrawal inclined surface, and the radius of the transition fillet is R4-R5.

[0018] Advantageously, the present invention provides a transition fillet between the arched surface forming portion and the stripping slope, and the radius of the transition fillet is R4-R5, thereby making the transition of the arched surface of the arched eccentric sleeve blank between the arched surface forming portion and the stripping slope smoother.

[0019] According to a method for manufacturing an arched eccentric sleeve according to an embodiment of the present invention, the sintering temperature of the sintering step is set to 1120°C.

[0020] Advantageously, the present invention sets the sintering temperature of the sintering step to 1120° C. so that the sintering temperature can reach about 80% of the melting point of the main component iron of the powder, thereby meeting the sintering temperature requirement of the arched eccentric sleeve blank.

[0021] According to a method for manufacturing an arched eccentric sleeve according to an embodiment of the present invention, a first finishing step is further included between the sintering step and the heat treatment step, and the first finishing step removes burrs from the arched eccentric sleeve blank obtained in the sintering step.

[0022] The benefit is that: the present invention sets a first finishing step between the sintering step and the heat treatment step, and the first finishing step removes burrs from the arched eccentric sleeve blank obtained in the sintering step, thereby enabling the burrs of the arched eccentric sleeve blank to be removed after the sintering step and the heat treatment step. It should be explained that the arched eccentric sleeve blank has a low structural hardness before sintering, and the burr removal treatment is likely to damage the arched eccentric sleeve blank, while the hardness of the arched eccentric sleeve blank is too high after the heat treatment, and it is difficult to remove the burrs. By removing the burrs from the arched eccentric sleeve blank between the sintering step and the heat treatment step, the difficulty of burr removal can be reduced while protecting the arched eccentric sleeve blank from damage.

[0023] According to a method for manufacturing an arched eccentric sleeve according to an embodiment of the present invention, a second finishing step is further provided after the heat treatment step, and the second finishing step removes surface dirt from the arched eccentric sleeve blank obtained in the heat treatment step.

[0024] Advantageously, the present invention further provides a second polishing step after the heat treatment step, and the second polishing step removes surface dirt from the arched eccentric sleeve blank obtained in the heat treatment step. It is understandable that dirt will remain on the surface of the arched eccentric sleeve blank after the heat treatment, and the second polishing step can clean the surface dirt generated in the heat treatment step, thereby making the surface of the arched eccentric sleeve blank smoother.

[0025] According to a method for manufacturing an arched eccentric sleeve according to an embodiment of the present invention, a centerless grinding step is further provided after the second finishing step, in which the arched eccentric sleeve blank is continuously placed in a V-shaped guide rail, the product is pushed forward, and ground by a double grinding wheel in two steps; the first grinding to ; Second grinding to .

[0026] Advantageously, the present invention further provides a centerless grinding step after the second finishing step, in which the arched eccentric sleeve blank is continuously placed in the V-shaped guide rail, the product is pushed forward, and the double grinding wheels are used for grinding, which is divided into two grinding steps; the first grinding to ; Second grinding to Therefore, the centerless grinding step can grind the outer diameter of the arched eccentric sleeve blank with higher accuracy.

[0027] According to a method for manufacturing an arched eccentric sleeve according to an embodiment of the present invention, a milling step is further provided after the centerless grinding step, in which a milling fixture is put on the arched eccentric sleeve blank, the milling fixture supports the polygonal inner hole of the arched eccentric sleeve to clamp the arched eccentric sleeve, and then a grinding wheel is used to grind a 12.4 mm distance from the axis of the arched eccentric sleeve on the outer peripheral surface of the arched eccentric sleeve. The first plane is 0.1mm, and then one end of the arched eccentric sleeve is rounded by R0.6~R0.9, the arched eccentric sleeve is turned over and mounted on the milling fixture, and then the other end of the arched eccentric sleeve is rounded by R0.6~R0.9.

[0028] Advantageously, the present invention further comprises a milling step after the centerless grinding step, wherein the milling step is to put a milling fixture on the arched eccentric sleeve blank, the milling fixture supports the polygonal inner hole of the arched eccentric sleeve to clamp the arched eccentric sleeve, and then a grinding wheel is used to grind a 12.4 mm distance from the axis of the arched eccentric sleeve on the outer peripheral surface of the arched eccentric sleeve. The first plane is 0.1mm, and then one end of the arched eccentric sleeve is chamfered by R0.6~R0.9, the arched eccentric sleeve is turned over and mounted on the milling fixture, and then the other end of the arched eccentric sleeve is chamfered by R0.6~R0.9. Thus, the shape of the arched eccentric sleeve is carried out through the milling process, so as to form an arched eccentric sleeve of designed shape.

[0029] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions of the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1 It is a structural schematic diagram of an arched eccentric sleeve according to an embodiment of the present invention; Figure 2 for Figure 1 AA cross-sectional view shown; Figure 3 A process flow chart of a method for manufacturing an arched eccentric sleeve according to an embodiment of the present invention; Figure 4 It is a structural comparison diagram of a mold in a demoulding state and a powder filling state in a method for manufacturing an arched eccentric sleeve according to an embodiment of the present invention; Figure 5 for Figure 4 A schematic diagram of the structure of the main core rod shown; Figure 6 for Figure 5 A partial enlarged view of the arched surface forming portion of the main core rod is shown; Figure 7 for Figure 4 The schematic structural diagram of the female mold shown; Figure 8 for Figure 4 The structural schematic diagram of the lower punch die shown; Fig. 9 The present invention is a schematic structural diagram of an upper punch die of a mold in a method for manufacturing an arched eccentric sleeve according to an embodiment of the present invention.

[0032] Figure markings: 100-polygonal inner hole, 110-arched surface, 120-cavity, 130-lower punch, 140-main core rod, 150-female die, 160-upper punch, 170-arched surface forming part, 180-removal slope, 190-transition radius, 200-core rod seat, 210-core rod pad, 220-core rod pressure cover, 230-rod cap, 240-lower punch seat cushion, 250-lower punch seat, 260-lower punch pad, 270-lower punch cover, 280-die cap. DETAILED DESCRIPTION

[0033] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0034] In the description of the present invention, it is necessary to understand that descriptions involving orientation, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0035] In the description of the present invention, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed", etc. are understood to exclude the number itself, and "above", "below", "within", etc. are understood to include the number itself. If there is a description of first and second, this is only for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0036] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation, connection and connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0037] A method for manufacturing an arched eccentric sleeve according to an embodiment of the present invention will be described below with reference to the accompanying drawings.

[0038] The present invention aims to provide an embodiment of a method for manufacturing an arched eccentric sleeve.

[0039] Reference Figure 1 and Figure 2 In this embodiment, a manufacturing method of an arched eccentric sleeve is used to form an arched eccentric sleeve with a convex middle and flat sides on one side of an inner hole. The outer shape of the arched eccentric sleeve is cylindrical. The arched eccentric sleeve has a polygonal inner hole 100 passing through both ends. One side surface of the polygonal inner hole 100 is an arched surface 110 with a convex middle and flat sides along the axial direction of the arched eccentric sleeve. Therefore, the surface contact on one side of the eccentric sleeve is changed to point contact, thereby improving the rotation effect of the eccentric sleeve. At the same time, the surface contact used to fix the transmission position of the eccentric sleeve is changed to point contact, thereby reducing the area of ​​the support position used to fix the transmission position of the eccentric sleeve, making it easier to control the size of the eccentric sleeve in production, ensuring that there is not much difference in the wear and performance of the eccentric sleeves produced in batches, and ensuring the consistency of the quality of batch production.

[0040] Specifically, the outer diameter of the arched eccentric sleeve is controlled within The profile of the arched surface 110 without a reference surface is controlled within 0.04 mm, and the surface profile of the arched surface 110 relative to the reference surface B is controlled within 0.15 mm.

[0041] Reference Figure 3 In this embodiment, a method for manufacturing an arched eccentric sleeve includes the following steps: Mixing step: Various raw material powders are mixed according to a set ratio to form a powder with iron powder as the main component.

[0042] Forming step: Powder is added into the mold cavity 120 of the mold, and the mold presses the powder in the mold cavity 120 to form an arched eccentric sleeve blank.

[0043] Reference Figure 4 , Figure 4 The left side is a schematic diagram of the structure of the mold in the demoulding state. Figure 4 The right side of the middle is a schematic diagram of the structure of the mold when it is filled with powder.

[0044] Reference Figure 5 , Figure 6 , Figure 7 , Figure 8 and Fig. 9Specifically, the mold includes a lower punch 130, a main core rod 140, a female die 150 and an upper punch 160. The lower punch 130 is mounted on the outside of the main core rod 140, the female die 150 is mounted on the outside of the lower punch 130, and the upper punch 160 is located above the lower punch 130. A cavity 120 is formed between the top of the lower punch 130, the outer peripheral surface of the main core rod 140, the inner peripheral surface of the female die 150 and the bottom end of the upper punch 160. One side of the main core rod 140 has an arched surface forming portion 170, and the arched surface forming portion 170 is concave in the middle and flat on both sides along the length direction of the main core rod 140.

[0045] It can be understood that by setting the arch surface forming part 170 on one side of the main core rod 140, the forming step can form the arch eccentric sleeve in one piece through the mold, eliminating the need to press the arch eccentric sleeve blank and then form the arch surface 110 through machining, thereby improving the production efficiency of the arch eccentric sleeve and the consistency of the quality of the produced arch eccentric sleeve.

[0046] In some specific embodiments, the mold also includes a mandrel seat 200, a mandrel pad 210 and a mandrel pressure cover 220. The mandrel pad 210 is arranged on the mandrel seat 200. The mandrel pad 210 is used to support the bottom end of the main mandrel 140. The bottom end of the main mandrel 140 has a rod cap 230. The mandrel pressure cover 220 is used to be inserted outside the rod cap 230 to press and fix the main mandrel 140.

[0047] In some specific embodiments, the mold also includes a lower punch seat 250 pad 240, a lower punch seat 250, a lower punch pad plate 260 and a lower punch cover 270. The lower punch seat 250 is arranged on the lower punch seat 250 pad 240, the lower punch pad plate 260 is arranged on the lower punch seat 250, the lower punch pad plate 260 is used to support the bottom end of the lower punch die 130, the bottom end of the lower punch die 130 has a die cap 280, and the lower punch cover 270 is used to be mounted on the outside of the die cap 280 to press and fix the lower punch die 130.

[0048] In some specific embodiments, the molding step includes powder loading, pressing and demolding in sequence. In the powder loading, the lower punch 130 does not move, the top surfaces of the main core rod 140 and the female mold 150 are flush and higher than the top surface of the lower punch 130, and then the powder is loaded into the cavity 120. In the pressing, the upper punch 160 is inserted downward into the female mold 150 to extrude the powder in the cavity 120 to form the powder. In the demolding, the lower punch 130 does not move, the upper punch 160 is separated from the female mold 150 upward, and the female mold 150 is separated from the arched eccentric sleeve blank downward, and then the arched eccentric sleeve blank is clamped with a clamp, and the main core rod 140 is separated from the polygonal inner hole 100 of the arched eccentric sleeve downward.

[0049] In this embodiment, during the powder filling action, the lower punch 130 is stationary, the top surfaces of the main core rod 140 and the female die 150 are flush with and higher than the top surface of the lower punch 130, and then powder is filled into the cavity 120, so that the gap between the main core rod 140, the female die 150 and the top surface of the lower punch 130 forms the cavity 120. During the pressing action, the upper punch 160 is inserted downward into the female die 150 to squeeze the powder in the cavity 120 into a mold, so that the upper punch 160 can be inserted into the cavity 120, so that the upper punch 160, the main core rod 140, the female die 150 and the lower punch 130 cooperate to squeeze the powder in the cavity 120. During the demolding operation, the lower punch 130 does not move, the upper punch 160 is separated from the female die 150 upward, the female die 150 is separated from the arched eccentric sleeve blank downward, and then the arched eccentric sleeve blank is clamped with a clip, and the main core rod 140 is separated from the polygonal inner hole 100 of the arched eccentric sleeve downward. It can be understood that during demolding, the female die 150 is first separated from the arched eccentric sleeve blank downward, so that the outer contour of the arched eccentric sleeve blank is first separated from the restraint of the female die 150. At this time, the inner contour of the arched eccentric sleeve is still supported by the main core rod 140, so that the outer contour of the arched eccentric sleeve blank will not affect the arch when it is demolded and rebounded. The inner contour size of the eccentric sleeve avoids the outer contour of the arched eccentric sleeve blank affecting the inner contour size of the arched eccentric sleeve blank during demoulding and rebounding, thereby reducing the factors affecting the inner contour size of the arched eccentric sleeve blank during demoulding, making the inner contour size of the arched eccentric sleeve blank more stable, and making the size of the arched surface 110 of the pressed arched eccentric sleeve more accurate. After the female mold 150 is separated from the arched eccentric sleeve blank, the arched eccentric sleeve blank is clamped with a clamp, and then the main core rod 140 is downwardly separated from the polygonal inner hole 100 of the arched eccentric sleeve blank, so that the clamp can be demoulded on the main core rod 140. The arched eccentric sleeve blank is clamped at the same time, so that the arched eccentric sleeve is more stable, so that the main core rod 140 can be smoothly demoulded from the polygonal inner hole 100 of the arched eccentric sleeve blank. When the main core rod 140 is demoulded, the arched surface 110 of the arched eccentric sleeve is squeezed by the main core rod 140 when the main core rod 140 moves, and can rebound and recover after demoulding by utilizing the demoulding rebound characteristics. Because when the main core rod 140 is demoulded, only the inner contour of the arched eccentric sleeve blank rebounds, there are fewer factors that affect the inner contour size of the arched eccentric sleeve blank, thereby making the size of the arched surface 110 of the formed arched eccentric sleeve accessory more stable.

[0050] In some specific embodiments, the maximum arch height of the arch surface 110 is 0.03 0.02mm, the maximum depression depth of the arched surface forming portion 170 is 0.045 0.003mm.

[0051] In this embodiment, the maximum arch height of the arch surface 110 is set to 0.03 0.02 mm, so that the maximum arch height of the arched surface 110 is relatively small, which in turn facilitates demolding of the main core rod 140 in the molding step.

[0052] At the same time, the maximum depression depth of the arched surface forming portion 170 is 0.045 0.003mm. It can be understood that after the arch surface 110 is formed, the arch surface 110 will be squeezed by the main core rod 140 when the main core rod 140 is demolded. After demolding, the arch surface 110 will recover its size by rebounding, but the rebounded size will be smaller than the formed size, so that the maximum depression depth of the arch surface forming part 170 is designed to be controlled within the upper difference range of the maximum arch height of the arch surface 110, so that the size of the arch surface 110 formed can compensate for the size of the arch surface 110 that is reduced after being squeezed and rebounded by the main core rod 140 when the main core rod 140 is demolded, thereby making the size of the arch surface 110 recovered by rebound after the main core rod 140 is demolded can be within the size range of the designed maximum arch height of the arch surface 110.

[0053] In some specific embodiments, the main core rod 140 is also provided with a material withdrawal slope 180, which is located on the side of the arch surface forming part 170 close to the upper punch 160. Therefore, when the main core rod 140 is demolded, the arch surface 110 of the arched eccentric sleeve blank can immediately enter the material withdrawal slope 180 of the main core rod 140 after leaving the arch surface forming part 170 of the main core rod 140, so that the arch surface 110 of the arched eccentric sleeve blank can rebound in the material withdrawal slope 180 to restore the arch shape of the arch surface 110, thereby avoiding the main core rod 140 squeezing the arch surface 110 of the arched eccentric sleeve blank for a long time, resulting in the arch surface 110 being unable to restore the arch shape through demolding rebound.

[0054] In some specific embodiments, there is a transition fillet 190 between the arched surface forming portion 170 and the stripping slope 180, and the radius of the transition fillet 190 is R4-R5, so that the transition between the arched surface 110 of the arched eccentric sleeve blank and the arched surface forming portion 170 and the stripping slope 180 is smoother.

[0055] Sintering step: heating and keeping the arched eccentric sleeve blank obtained in the forming step in a protective gas for sintering.

[0056] In this embodiment, a sintering step is provided, in which the arched eccentric sleeve blank obtained in the forming step is heated and kept warm in a protective gas for sintering. Thus, during the sintering process, the bonding force between the powder particles is enhanced to form a solid metal body.

[0057] In some specific embodiments, the sintering temperature of the sintering step is set to 1120°C.

[0058] In this embodiment, the sintering temperature of the sintering step is set to 1120° C. so that the sintering temperature can reach about 80% of the melting point of the main component iron of the powder, thereby meeting the sintering temperature requirement of the arched eccentric sleeve blank.

[0059] The first finishing step: The first finishing step is to remove burrs from the arched eccentric sleeve blank obtained in the sintering step.

[0060] In this embodiment, a first finishing step is arranged between the sintering step and the heat treatment step. The first finishing step removes burrs from the arched eccentric sleeve blank obtained in the sintering step, thereby enabling the burrs of the arched eccentric sleeve blank to be removed after the sintering step and the heat treatment step. It should be explained that the arched eccentric sleeve blank has a low structural hardness before sintering, and the burr removal treatment may easily damage the arched eccentric sleeve blank. However, the hardness of the arched eccentric sleeve blank is too high after the heat treatment, and it is difficult to remove the burrs. By removing the burrs from the arched eccentric sleeve blank between the sintering step and the heat treatment step, the difficulty of burr removal can be reduced while protecting the arched eccentric sleeve blank from damage.

[0061] Heat treatment step: heat treat the arched eccentric sleeve blank.

[0062] In this embodiment, a heat treatment step is provided, in which the arched eccentric sleeve blank is heat-treated, thereby improving the hardness of the arched eccentric sleeve.

[0063] Specifically, the center position of the arched eccentric sleeve blank along the axial direction requires the heat treatment hardness to be above HRC35. Second finishing step: The second finishing step is to remove surface dirt from the arched eccentric sleeve blank obtained in the heat treatment step.

[0064] In this embodiment, a second polishing step is further provided after the heat treatment step. The second polishing step removes surface dirt from the arched eccentric sleeve blank obtained in the heat treatment step. It can be understood that dirt will remain on the surface of the arched eccentric sleeve blank after the heat treatment. The second polishing step can clean the surface dirt generated in the heat treatment step, thereby making the surface of the arched eccentric sleeve blank smoother.

[0065] Centerless grinding steps: Place the arched eccentric sleeve blanks into the V-shaped guide rail continuously, push the product forward, and grind it with double grinding wheels in two steps; the first grinding is to ; Second grinding to .

[0066] In this embodiment, a centerless grinding step is further provided after the second finishing step. In the centerless grinding step, the arched eccentric sleeve blank is continuously placed in the V-shaped guide rail, the product is pushed forward, and the double grinding wheel is used for grinding. The grinding is divided into two times; the first grinding to ; Second grinding to Therefore, the centerless grinding step can grind the outer diameter of the arched eccentric sleeve blank with higher accuracy.

[0067] Specifically, after the arched eccentric sleeve blank is ground in the centerless grinding step, the surface roughness of the arched eccentric sleeve is controlled within Ra0.3, and the cylindricity is controlled within 0.005 mm.

[0068] Milling process: put the arched eccentric sleeve blank on the milling fixture, the milling fixture holds the polygonal inner hole of the arched eccentric sleeve 100 to clamp the arched eccentric sleeve, and then use a grinding wheel to grind a distance of 12.4 from the axis of the arched eccentric sleeve on the outer peripheral surface of the arched eccentric sleeve. The first plane is 0.1mm, and then one end of the arched eccentric sleeve is rounded by R0.6~R0.9, the arched eccentric sleeve is turned over and mounted on the milling fixture, and then the other end of the arched eccentric sleeve is rounded by R0.6~R0.9.

[0069] In this embodiment, a milling process is provided after the centerless grinding process. In the milling process, the arched eccentric sleeve blank is put on a milling fixture. The milling fixture supports the polygonal inner hole 100 of the arched eccentric sleeve to clamp the arched eccentric sleeve, and then a grinding wheel is used to grind a 12.4 mm distance from the axis of the arched eccentric sleeve on the outer peripheral surface of the arched eccentric sleeve. The first plane is 0.1mm, and then one end of the arched eccentric sleeve is chamfered by R0.6~R0.9, the arched eccentric sleeve is turned over and mounted on the milling fixture, and then the other end of the arched eccentric sleeve is chamfered by R0.6~R0.9. Thus, the shape of the arched eccentric sleeve is carried out through the milling process, so as to form an arched eccentric sleeve of designed shape.

[0070] Double-end grinding steps: Place the arched eccentric sleeve on the carrier plate of the double-sided grinding machine, and use the double-sided grinding machine to grind the two end faces of the arched eccentric sleeve. After grinding, the total height of the arched eccentric sleeve is controlled within 27 The roughness of the end surface is controlled within Ra0.8, the flatness is controlled within 0.01mm, and the parallelism is controlled within 0,02mm.

[0071] Trimming steps: remove dirt from the grooves of the arched eccentric sleeve.

[0072] Demagnetization steps: remove the residual magnetism of the arched eccentric sleeve.

[0073] Cleaning steps: Clean and remove dirt from the surface of the arched eccentric sleeve.

[0074] Inspection steps: Carry out dimensional inspection and full appearance inspection on the arched eccentric sleeve.

[0075] Specifically, the inspection step includes detecting the contour of the arched surface 110, placing the arched eccentric sleeve on a three-coordinate detection device, and using the three-coordinate device to scan the contour of the arched surface 110 of the arched eccentric sleeve, and detecting the surface contour of the arched surface 110 without a reference and the surface contour of the arched surface 110 relative to the reference surface B of the arched eccentric sleeve, thereby ensuring that the contour of the pressed arched surface 110 is qualified.

[0076] The contours of the arched surfaces 110 of 11 arched eccentric sleeves were randomly tested using a three-coordinate device, and the test results shown in Table 1 were obtained:

[0077] Table 1 It can be seen from the test results in Table 1 above that the contours of the arched surface 110 of the 11 randomly selected arched eccentric sleeves tested are all qualified. Therefore, the contour of the arched surface 110 of the arched eccentric sleeve manufactured by the manufacturing method of the arched eccentric sleeve of this embodiment is stable, the demolding of the main core rod of the mold and the rebound of the arched surface 110 have little effect on the size of the arched surface 110, and the size of the arched eccentric sleeve is stable.

[0078] Oil immersion step: immerse the arched eccentric sleeve in oil to prevent the arched eccentric sleeve from rusting.

[0079] Packaging steps: pack the qualified arched eccentric sleeves in the inspection step into boxes.

[0080] In the description of this specification, the description with reference to the terms "one embodiment, some embodiments, illustrative embodiments, examples, specific examples or some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0081] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. A method for manufacturing an arched eccentric sleeve, characterized in that: An arched eccentric sleeve for forming an inner hole with one side convex in the middle and two flat sides, the outer shape of the arched eccentric sleeve being cylindrical, the arched eccentric sleeve having a polygonal inner hole (100) penetrating two ends, one side surface of the polygonal inner hole (100) being an arched surface (110) with a convex middle and two flat sides along the axial direction of the arched eccentric sleeve, the manufacturing method comprising the following steps: Forming step: adding powder into a mold cavity (120) of a mold, wherein the mold presses the powder in the mold cavity (120) to form an arched eccentric sleeve blank; The mold comprises a lower punch (130), a main core rod (140), a female mold (150) and an upper punch (160); the lower punch (130) is sleeved outside the main core rod (140); the female mold (150) is sleeved outside the lower punch (130); the upper punch (160) is located above the lower punch (130); the top of the lower punch (130), the outer peripheral surface of the main core rod (140), the inner peripheral surface of the female mold (150) and the bottom of the upper punch (160) form the mold cavity (120); one side surface of the main core rod (140) has an arched surface forming portion (170); the arched surface forming portion (170) is concave in the middle and flat on both sides along the length direction of the main core rod (140); Sintering step: heating and keeping the arched eccentric sleeve blank obtained in the forming step in a protective gas for sintering; Heat treatment step: heat treat the arched eccentric sleeve blank.

2. The method for manufacturing an arched eccentric sleeve according to claim 1, characterized in that: The molding step includes powder loading, pressing, and demoulding in sequence. In the powder loading, the lower punch (130) remains stationary, the top surfaces of the main core rod (140) and the female die (150) are flush with and higher than the top surface of the lower punch (130), and then powder is loaded into the cavity (120). In the pressing, the upper punch (160) is inserted downward into the female die (150) to squeeze the powder in the cavity (120) for molding. In the demoulding, the lower punch (130) remains stationary, the upper punch (160) is separated from the female die (150) upward, and the female die (150) is separated from the arched eccentric sleeve blank downward. Then, the arched eccentric sleeve blank is clamped with a clamp, and the main core rod (140) is separated from the polygonal inner hole (100) of the arched eccentric sleeve downward.

3. The method for manufacturing an arched eccentric sleeve according to claim 1, characterized in that: The maximum arch height of the arched surface (110) is 0.03 0.02mm, the maximum concave depth of the arched surface forming portion (170) is 0.045 0.003mm.

4. The method for manufacturing an arched eccentric sleeve according to claim 1, characterized in that: The main core rod (140) is also provided with a material stripping inclined surface (180), and the material stripping inclined surface (180) is located on a side of the arched surface forming portion (170) close to the upper punch die (160).

5. The method for manufacturing an arched eccentric sleeve according to claim 4, characterized in that: A transition fillet (190) is provided between the arched surface forming portion (170) and the material withdrawal inclined surface (180), and the radius of the transition fillet (190) is R4-R5.

6. The method for manufacturing an arched eccentric sleeve according to claim 1, characterized in that: The sintering temperature of the sintering step was set to 1120°C.

7. The method for manufacturing an arched eccentric sleeve according to claim 1, characterized in that: A first finishing step is also included between the sintering step and the heat treatment step, and the first finishing step removes burrs from the arched eccentric sleeve blank obtained in the sintering step.

8. The method for manufacturing an arched eccentric sleeve according to claim 1, characterized in that: A second finishing step is further provided after the heat treatment step, and the second finishing step removes surface dirt from the arched eccentric sleeve blank obtained in the heat treatment step.

9. The method for manufacturing an arched eccentric sleeve according to claim 8, characterized in that: After the second finishing step, a centerless grinding step is also provided, in which the arched eccentric sleeve blank is continuously placed in the V-shaped guide rail, the product is pushed forward, and the double grinding wheel is used for grinding, which is divided into two grinding steps; the first grinding to ; Second grinding to .

10. The method for manufacturing an arched eccentric sleeve according to claim 9, characterized in that: After the centerless grinding step, a milling step is further provided, wherein the arched eccentric sleeve blank is placed on a milling fixture, the milling fixture supports the polygonal inner hole (100) of the arched eccentric sleeve to clamp the arched eccentric sleeve, and then a grinding wheel is used to grind a groove on the outer peripheral surface of the arched eccentric sleeve with a distance of 12.4 from the axis of the arched eccentric sleeve. The first plane is 0.1mm, and then one end of the arched eccentric sleeve is rounded by R0.6~R0.9, the arched eccentric sleeve is turned over and mounted on the milling fixture, and then the other end of the arched eccentric sleeve is rounded by R0.6~R0.9.

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