A kind of vane pump shell flow channel surface finishing tool and method

Abstract

The application discloses a kind of blade pump shell flow channel surface finishing toolings, including upper cover plate, lower cover plate, support ring, first processing module and second processing module;Upper cover plate, lower cover plate and support ring form annular cavity for accommodating pump shell;First through hole is provided on the upper cover plate, and abrasive enters upper abrasive cylinder from annular cavity through first through hole, or enters annular cavity from upper abrasive cylinder through first through hole;Second through hole is provided on the lower cover plate;First processing module is used to install at second through hole during first time abrasive flow processing, including annular structure and arc boss connected to the inner wall of annular structure;Second processing module is used to install at second through hole during second time abrasive flow processing, and it is annular structure.The application also discloses a kind of finishing methods realized using above tooling, respectively using first, second processing module realizes the step-by-step finishing machining of blade pump shell, effectively improves processing quality.

Description

Technical Field

[0001] This invention belongs to the field of finishing technology for metal parts, specifically relating to an abrasive flow finishing fixture and method for the surface of a vane pump housing flow channel. Background Technology

[0002] The vane pump housing is a key component of a turbopump in an engine, requiring extremely high surface roughness for the vanes and turbine passages. Because it is produced using selective laser melting, the surface roughness of the vanes and turbine passages is poor and cannot meet the requirements, thus necessitating further finishing.

[0003] Traditional surface finishing methods include sandblasting, shot peening, and manual / mechanical grinding, which cannot meet the surface roughness requirements. The sand used in sandblasting and shot peening cannot reach the back of the blade and the inside of the vortex channel, and the tools used in manual / mechanical grinding are hard contact tools that can easily damage the blade, thus failing to achieve high-quality finishing. Summary of the Invention

[0004] The purpose of this invention is to overcome the above-mentioned defects and provide a finishing fixture and method for the surface of the flow channel of a vane pump housing. This invention solves the technical problem that traditional methods cannot achieve the finishing of the vortex channel and vane surface of a vane pump housing by laser selective melting. This invention can realize the step-by-step finishing process of the vane pump housing and effectively improve the processing quality.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0006] A surface finishing fixture for the flow channel of a vane pump housing includes an upper cover plate, a lower cover plate, a support ring, a first processing module, and a second processing module.

[0007] The upper cover plate is supported above the lower cover plate by a support ring, and the upper cover plate, the lower cover plate and the support ring form an annular cavity for accommodating the pump housing;

[0008] The upper cover plate is provided with a first through hole, through which the abrasive enters the upper abrasive cylinder from the annular cavity through the first through hole, or through the upper abrasive cylinder into the annular cavity from the first through hole;

[0009] A second through hole is provided on the lower cover plate;

[0010] The first processing module is installed at the second through hole during the first abrasive flow processing. It includes an annular structure and an arc-shaped boss connected to the inner wall of the annular structure. The central angle of the arc-shaped boss is 120° to 240°. The annular structure mates with the flange end face of the pump housing, and the arc-shaped boss mates with the annular groove in the pump housing where blades are provided, thereby sealing some of the blades. During the first abrasive flow processing, the abrasive material passes sequentially from the lower abrasive cylinder through the second through hole, the inside of the first processing module, and the unsealed blades of the pump housing into the inside of the pump housing, or sequentially from the inside of the pump housing through the unsealed blades of the pump housing, the inside of the first processing module, and the second through hole into the lower abrasive cylinder.

[0011] The second processing module, an annular structure, is installed at the second through-hole during the second abrasive flow machining process. It mates with the flange face of the pump housing. During the second abrasive flow machining, the abrasive material enters the pump housing sequentially from the lower abrasive cylinder through the second through-hole, the interior of the second processing module, and the pump housing blades, or sequentially from the pump housing interior through the pump housing blades, the interior of the second processing module, and the second through-hole. The height of the pump housing's central column is higher than the flange face, so the second processing module is needed to elevate the flange face. Otherwise, after the first module is removed, the central column will be inserted into the eccentric hole of the lower cover plate, preventing the pump housing from being clamped and fixed axially, thus failing to achieve axial positioning.

[0012] Furthermore, the central angle corresponding to the arc-shaped boss in the first processing module is 180°.

[0013] Furthermore, in the first processing module, the height of the arc-shaped boss is higher than the height of the annular structure; the height difference between the arc-shaped boss and the annular structure is equal to the height difference between the flange end face of the pump housing and the blade.

[0014] Furthermore, when the first processing module or the second processing module is installed at the second through hole, the lower end of the central column is flush with the upper end of the second through hole or the lower end of the central column is located inside the second through hole.

[0015] Furthermore, the annular structure in the first processing module is a combination of two independent semicircular structures, with an arc-shaped boss connected to the inner wall of one of the semicircular structures.

[0016] When the first processing module is installed at the second through hole, the two semi-circular structures are pressed together to form a ring structure.

[0017] Furthermore, in the lower cover plate, an annular recessed step is provided on the outside of the second through hole. When the first processing module or the second processing module is installed at the second through hole, the first processing module or the second processing module cooperates with the recessed step, that is, the outer side (cylindrical surface) of the first processing module or the second processing module cooperates with the inner side of the recessed step to achieve radial limiting of the first processing module or the second processing module.

[0018] During the first abrasive flow machining, the upper end face of the annular structure in the first machining module mates with the flange end face of the pump housing, the lower end face mates with the bottom of the recessed step on the lower cover plate, and the upper cover plate mates with the upper end of the pump housing. The upper and lower cover plates are used to achieve axial positioning of the pump housing.

[0019] During the second abrasive flow machining, the upper end face of the second machining module mates with the flange end face of the pump housing, the lower end face mates with the bottom of the recessed step on the lower cover plate, and the upper cover plate mates with the upper end of the pump housing. The upper and lower cover plates are used to achieve axial positioning of the pump housing.

[0020] Furthermore, in the first processing module, the inner diameter of the annular structure is equal to the outer diameter of the annular groove in the pump housing, and the width of the arc-shaped boss is equal to the width of the annular groove in the pump housing.

[0021] The inner diameter of the second processing module is equal to the outer diameter of the annular groove in the pump housing.

[0022] The second through hole is an eccentric hole.

[0023] A method for surface finishing of the flow channel of a vane pump casing, implemented using the aforementioned surface finishing fixture for the flow channel of a vane pump casing, includes:

[0024] First abrasive flow machining:

[0025] S1.1 The first processing module is installed at the second through hole, so that the annular structure in the first processing module matches the flange end face of the pump housing, and the arc-shaped boss matches the annular groove in the pump housing where the blades are located, thereby achieving the sealing of some blades.

[0026] S1.2 causes the abrasive to reciprocate between the upper abrasive cylinder, the tooling, and the lower abrasive cylinder, thereby achieving the finishing of the flow channel surfaces other than the blocked blades;

[0027] S1.3 Rotate the first processing module by a predetermined angle and repeat step S1.2;

[0028] S1.4 Repeat step S1.3 until all blades have been finished.

[0029] Second abrasive flow machining:

[0030] S2.1 Remove the first processing module and install the second processing module at the second through hole, so that the second processing module mates with the flange end face of the pump housing;

[0031] S2.2 causes the abrasive to reciprocate between the upper abrasive cylinder, the tooling, and the lower abrasive cylinder, thereby achieving a second finishing of the pump housing flow channel surface.

[0032] Furthermore, in step S1.2, the path of the abrasive's reciprocating motion is as follows:

[0033] Lower abrasive cylinder - second through hole - inside the first processing module - unblocked blades of the pump housing - inside the pump housing - conical outlet of the pump housing - other spaces outside the pump housing in the annular cavity - first through hole - upper abrasive cylinder;

[0034] In step S2.2, the path of the abrasive's reciprocating motion is as follows:

[0035] Lower abrasive cylinder - second through hole - inside of the second processing module - pump housing blade - inside of the pump housing - conical outlet of the pump housing - other spaces outside the pump housing in the annular cavity - first through hole - upper abrasive cylinder.

[0036] Furthermore, the central angle corresponding to the arc-shaped boss in the first processing module is 180°;

[0037] In step S1.3, the first processing module is rotated 90°, and step S1.2 is repeated.

[0038] S1.4 Repeat step S1.3 to rotate the first processing module a total of 4 times, so that all blades are finished.

[0039] Furthermore, the processing parameters for the first abrasive flow machining are: processing pressure 2-4 MPa, number of machining passes (one pass includes one round trip of the abrasive) 3-5 times, and abrasive volume of 700-800 cm³ per pass. 3 The first processing module rotates to one position and processes 3 to 5 times.

[0040] The processing parameters for the second abrasive flow machining are: processing pressure 2-4 MPa, number of processing passes 12-15, and abrasive material volume of 700-800 cm³ per pass. 3 .

[0041] Compared with the prior art, the present invention has at least one of the following advantages:

[0042] (1) This invention creatively proposes a special tooling for abrasive flow. Using this tooling, different processing parameters and step-by-step processing methods are adopted to achieve effective finishing of the internal flow channel and blades, thereby effectively improving the product processing quality.

[0043] (2) By setting a first processing module with an arc-shaped boss, the present invention forces the abrasive to pass through the set channel for processing, resulting in a better and more uniform finishing effect.

[0044] (3) The present invention performs the first processing by rotating the first processing module multiple times and performs the second processing by using the second processing module, which effectively eliminates the rotational joints caused by the first processing module and can obtain products with high smoothness.

[0045] (4) The first processing module and the second processing module of the present invention have simple structures and are easy to process. The first processing module is designed as a splicing structure of two semicircles, which further reduces the difficulty of the process and is conducive to large-scale application. Attached Figure Description

[0046] Figure 1 This is a schematic diagram of the casing of a vane pump; where (a) is a perspective view and (b) is a top view.

[0047] Figure 2 This is a schematic diagram of the surface finishing fixture for the flow channel of the impeller pump housing of the present invention during the first processing.

[0048] Figure 3 This is a schematic diagram of the surface finishing fixture for the flow channel of the impeller pump housing of the present invention during the second processing.

[0049] Figure 4 This is a schematic diagram of the structure of the first processing module and the second processing module of the present invention; wherein, (a) is the first processing module and (b) is the second processing module;

[0050] Figure 5 This is a schematic diagram of the first processing module of the present invention and its cooperation with the pump housing; wherein (a) is a top view and (b) is a perspective view;

[0051] In the figure, 1-upper cover plate, 2-lower cover plate, 3-support ring, 4-first processing module, 5-second processing module, 6-conical outlet, 7-flange end face, 8-pump housing with vanes, 11-first through hole, 21-second through hole. Detailed Implementation

[0052] The features and advantages of the present invention will become clearer and more apparent from the following detailed description.

[0053] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments. Although various aspects of embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless specifically indicated otherwise.

[0054] The conical outlet of the pump casing and the blade clearance serve as the inlet and outlet for reciprocating abrasive flow machining. Due to the structure of the pump casing, the abrasive flows into the inlet, turns 90°, and then flows out from the outlet. Since abrasive, as a fluid, always flows along the shortest path, if there are no obstructions, the finishing effect of the blades and vortex channels near the conical outlet is relatively good, while the finishing effect is poor far from the conical outlet.

[0055] This invention proposes a surface finishing fixture for the flow channel of a pump housing with vanes, comprising a general part and a replaceable part. The general part includes an upper cover plate, a support ring, and a lower cover plate. The upper cover plate is provided with holes for abrasive machining inlet and outlet, and the lower cover plate is provided with an eccentric hole. The eccentric hole is installed by mating with the pump housing flange end face through a first or second module.

[0056] The first processing module consists of two semi-circular rings that are adapted to the position and size of the pump housing blades. The outer diameters of the two semi-circular rings are consistent. One of the semi-circular rings has a boss at its inner diameter position. The height difference between the boss and the semi-circular ring is consistent with the depth of the annular groove of the pump housing. The first processing module is adapted to the size of the eccentric hole of the lower cover plate and is installed in the position of the eccentric hole. The two semi-circular rings of the first processing module are close together (no connection required) to form a complete circle that fits with the end face of the pump housing flange. One half of the ring can completely block half of the pump housing blades, so that the abrasive only passes through the other half of the ring.

[0057] The second processing module is a ring that adapts to the position and size of the pump housing blades.

[0058] The upper end face of the eccentric hole (second through hole) is provided with a recessed step (which can also be considered as an annular groove). The height of the recessed step is preferably 1-5mm. The outer diameter of the two processing modules is adapted to the diameter of the recessed step (slightly smaller than the diameter of the recessed step), so radial positioning can be guaranteed by the step. The axial direction is fitted with the end face of the pump housing flange in a compressed state, so axial positioning can also be guaranteed.

[0059] Based on the above tooling, this invention proposes a method for surface finishing of the flow channel of a vane pump housing, comprising:

[0060] Step 1: Perform the first abrasive flow machining using the general-purpose parts of the tooling and the first machining module.

[0061] Step 2: Perform a second abrasive flow machining using the general-purpose part of the tooling and the second machining module.

[0062] In step one, the general tooling part is combined with the first processing module to perform abrasive flow machining on the blade.

[0063] Since only half a blade ring is processed each time, there are abrasive flow machining marks at the junction of the two semicircles in the first processing module. To eliminate these marks while maintaining efficiency, both semicircles are rotated 90° simultaneously for abrasive flow machining again. The machining is completed when the blade is rotated 90° for the fourth time.

[0064] In step one, the abrasive flow machining parameters are: machining pressure 2-4 MPa, machining cycles 3-5 times, and abrasive material volume of 750 cm³ per cycle. 3 .

[0065] In step two, the general-purpose tooling, in conjunction with the second machining module, enables the finishing of the pump housing vortex channel. The method of assembling the second machining module with the general-purpose part is the same as that of the first machining module. The purpose is to smooth and eliminate the machining marks on the blades after the four machining processes in step one, and to make the finishing of all blades and vortex channels more uniform.

[0066] The abrasive flow machining parameters in step two are: machining pressure 3.0 MPa, 12-15 machining cycles, and 750 cm³ of abrasive material per cycle. 3 .

[0067] Example:

[0068] like Figure 1 As shown, the impeller pump housing of this invention is formed by laser selective melting. The impellers are distributed in a complete circle along the vortex channel of the pump housing. The vortex channel forms a conical outlet with a flange. The impeller pump housing has poor surface roughness, and abrasive flow machining is used for internal surface finishing. The structures of the first and second processing modules of this invention are as follows: Figure 4 As shown.

[0069] like Figure 2 (1) The vane pump housing is fitted with the tooling general part and the first processing module 4. The lower cover plate 2 is placed on the abrasive flow processing equipment, and the first processing module 4, pump housing, support ring 3, and upper cover plate 1 are installed in sequence, as follows. Figure 5 The first processing module 4 mates with the flange end face 7 of the pump housing. The processing pressure is set to 2-4 MPa, the processing number is 3-5 times, and the abrasive material volume per processing is 750 cm³. 3 During processing, the abrasive flows into the pump housing from the unsealed blade position of the first processing module 4 and exits from the conical outlet 6 (conical flange) of the pump housing, and performs reciprocating processing. After one processing cycle, the first processing module 4 maintains its relative position to the general part and rotates 90° around its own center (or other angles) to perform abrasive flow processing again.

[0070] The machining process is completed during the fourth 90° rotation of the abrasive flow.

[0071] like Figure 3 (2) Remove the first processing module 4, and then assemble the vane pump housing with the tooling general part and the second processing module 5. The lower cover plate 2 is placed on the abrasive flow processing equipment. The second processing module 5, pump housing, support ring 3, and upper cover plate 1 are installed in sequence. The second processing module 5 mates with the flange end face 7 of the pump housing. Set the processing pressure to 3.0 MPa, the number of processing times to 12-15, and the amount of abrasive material processed each time to 750 cm³. 3During processing, the abrasive flows in from all the blades of the pump housing and flows out from the conical flange of the pump housing, and performs reciprocating processing. Since the second processing module 5 does not restrict the flow of abrasive in different parts, it does not need to rotate.

[0072] The pump housing obtained using the tooling and method of this invention can reduce the surface roughness Ra value of the blade part from 8 μm to 1.6 μm, and the roughness of other flow channel parts can be reduced from 8 μm to Ra 3.2 to 6.3 μm, and can achieve uniform surface finishing of each part of the flow channel.

[0073] The present invention has been described in detail above with reference to specific embodiments and exemplary examples; however, these descriptions should not be construed as limiting the present invention. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and embodiments of the present invention without departing from the spirit and scope of the invention, and all such modifications and improvements fall within the scope of the present invention. The scope of protection of the present invention is defined by the appended claims.

[0074] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A method for surface finishing of the flow channel of a vane pump casing, characterized in that, The surface finishing of the flow channel of a pump housing with vanes is achieved by a surface finishing fixture, which includes an upper cover plate (1), a lower cover plate (2), a support ring (3), a first processing module (4), and a second processing module (5). The upper cover plate (1) is supported above the lower cover plate (2) by the support ring (3). The upper cover plate (1), the lower cover plate (2) and the support ring (3) form an annular cavity for accommodating the pump housing. The upper cover plate (1) is provided with a first through hole (11). The abrasive enters the upper abrasive cylinder through the first through hole (11) from the annular cavity, or enters the annular cavity through the first through hole (11) from the upper abrasive cylinder. The lower cover plate (2) is provided with a second through hole (21); The first processing module (4) is installed at the second through hole (21) during the first abrasive flow processing. It includes an annular structure and an arc-shaped boss connected to the inner wall of the annular structure. The central angle of the arc-shaped boss is 120°~240°. The annular structure is matched with the flange end face of the pump housing, and the arc-shaped boss is matched with the annular groove in the pump housing where blades are provided, so as to block some blades. During the first abrasive flow processing, the abrasive material enters the pump housing from the lower abrasive cylinder through the second through hole (21), the inside of the first processing module (4), and the unblocked blades of the pump housing, or enters the lower abrasive cylinder from the inside of the pump housing through the unblocked blades of the pump housing, the inside of the first processing module (4), and the second through hole (21). The second processing module (5) is installed at the second through hole (21) during the second abrasive flow processing. It is a ring structure and the second processing module (5) is fitted with the flange end face of the pump housing. During the second abrasive flow processing, the abrasive material enters the pump housing from the lower abrasive cylinder through the second through hole (21), the inside of the second processing module (5), and the blades of the pump housing, or enters the lower abrasive cylinder from the inside of the pump housing through the blades of the pump housing, the inside of the second processing module (5), and the second through hole (21). A method for finishing the surface of the flow channel of a vane pump casing includes: First abrasive flow machining: S1.1 The first processing module (4) is installed at the second through hole (21), so that the annular structure in the first processing module (4) matches the flange end face of the pump housing, and the arc-shaped boss matches the annular groove in the pump housing with blades, thereby achieving the sealing of some blades; S1.2 causes the abrasive to reciprocate between the upper abrasive cylinder, the tooling, and the lower abrasive cylinder, thereby achieving the finishing of the flow channel surfaces other than the blocked blades; S1.3 Rotate the first processing module (4) by a predetermined angle and repeat step S1.2; S1.4 Repeat step S1.3 until all blades have been finished. Second abrasive flow machining: S2.1 Remove the first processing module (4) and install the second processing module (5) at the second through hole (21) so that the second processing module (5) fits with the flange end face of the pump housing; S2.2 causes the abrasive to reciprocate between the upper abrasive cylinder, the tooling, and the lower abrasive cylinder, thereby achieving a second finishing of the pump housing flow channel surface.

2. The method for surface finishing of the flow channel of a vane pump casing according to claim 1, characterized in that, In step S1.2, the path of the abrasive's reciprocating motion is as follows: Lower abrasive cylinder - second through hole (21) - inside of the first processing module (4) - unblocked blades of the pump housing - inside of the pump housing - conical outlet of the pump housing - other spaces outside the pump housing in the annular cavity - first through hole (11) - upper abrasive cylinder; In step S2.2, the path of the abrasive's reciprocating motion is as follows: Lower abrasive cylinder - second through hole (21) - inside of the second processing module (5) - blade of pump housing - inside of pump housing - conical outlet of pump housing - other spaces outside the pump housing in the annular cavity - first through hole (11) - upper abrasive cylinder.

3. The method for surface finishing of the flow channel of a vane pump casing according to claim 1, characterized in that, The central angle corresponding to the arc-shaped boss in the first processing module (4) is 180°; In S1.3, the first processing module (4) is rotated 90°, and step S1.2 is repeated. S1.4 Repeat step S1.3 to rotate the first processing module (4) a total of 4 times so that all blades are finished.

4. The method for surface finishing of the flow channel of a vane pump casing according to claim 1, characterized in that, The processing parameters for the first abrasive flow machining are: processing pressure 2~4MPa, 3~5 processing cycles, and abrasive material volume of 700~800 cm³ per cycle. 3 ; The processing parameters for the second abrasive flow machining are: processing pressure 2~4MPa, number of processing cycles 12~15, and abrasive material volume of 700~800 cm³ per cycle. 3 .

5. The method for surface finishing of the flow channel of a vane pump casing according to claim 1, characterized in that, The central angle corresponding to the arc-shaped boss in the first processing module (4) is 180°.

6. The method for surface finishing of the flow channel of a vane pump casing according to claim 1, characterized in that, In the first processing module (4), the height of the arc-shaped boss is higher than the height of the ring structure; the height difference between the arc-shaped boss and the ring structure is equal to the height difference between the flange end face of the pump housing and the blade.

7. A method for surface finishing of the flow channel of a vane pump casing according to claim 5, characterized in that, The ring structure in the first processing module (4) is a combination of two independent semicircular structures, with the arc-shaped boss connected to the inner wall of one of the semicircular structures; When the first processing module (4) is installed at the second through hole (21), the two semi-circular structures are close to each other and combined into a ring structure.

8. The method for surface finishing of the flow channel of a vane pump casing according to claim 1, characterized in that, In the lower cover plate (2), an annular recessed step is provided on the outside of the second through hole (21). When the first processing module (4) or the second processing module (5) is installed at the second through hole (21), the first processing module (4) or the second processing module (5) cooperates with the recessed step to achieve radial limiting of the first processing module (4) or the second processing module (5). During the first abrasive flow processing, the upper end face of the annular structure in the first processing module (4) is matched with the flange end face of the pump housing, the lower end face is matched with the bottom of the sinking step set in the lower cover plate (2), and the upper cover plate (1) is matched with the upper end of the pump housing. The axial limit of the pump housing is achieved by using the upper cover plate (1) and the lower cover plate (2). During the second abrasive flow processing, the upper end face of the second processing module (5) is matched with the flange end face of the pump housing, the lower end face is matched with the bottom of the sinking step set on the lower cover plate (2), and the upper cover plate (1) is matched with the upper end of the pump housing. The axial positioning of the pump housing is achieved by using the upper cover plate (1) and the lower cover plate (2).

9. A method for surface finishing of the flow channel of a vane pump casing according to claim 1, characterized in that, In the first processing module (4), the inner diameter of the annular structure is equal to the outer diameter of the annular groove in the pump housing, and the width of the arc-shaped boss is equal to the width of the annular groove in the pump housing. The inner diameter of the second processing module (5) is equal to the outer diameter of the annular groove in the pump housing; The second through hole (21) is an eccentric hole.

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