CN111673385A

CN111673385A - Production method of closed impeller

Info

Publication number: CN111673385A
Application number: CN202010542714.0A
Authority: CN
Inventors: 张明成; 陈东亮; 杨宝银; 丁树立
Original assignee: Yangxin Dongtai Precision Metal Co ltd
Current assignee: Yangxin Dongtai Precision Metal Co ltd
Priority date: 2020-06-15
Filing date: 2020-06-15
Publication date: 2020-09-18

Abstract

The invention relates to a production method of a closed impeller, which comprises the following steps: s1, dividing the impeller into an impeller body and an upper runner cover, wherein the number of the upper runner cover corresponds to that of the impeller body, and the impeller body with an open runner part and the upper runner cover matched with the open runner part are obtained by respectively and independently processing; s2, processing the matching contour of the upper cover part of the corresponding missing flow channel on the impeller body, and making the size of the matching contour smaller than that of the upper cover of the flow channel processed in S2; s3, respectively carrying out interference fit on the upper covers of the flow channels processed in the S1 at the corresponding fit contours on the impeller body in the S2; and S4, processing a welding groove at the matching contour part of the previous step, and welding the impeller body and each flow channel upper cover into a whole through the welding groove. The invention has low production difficulty and high yield, and can greatly reduce the production cost of the closed impeller.

Description

Production method of closed impeller

Technical Field

The invention relates to the technical field of impeller processing, in particular to a production method of a closed impeller.

Background

Closed impellers are a product often encountered in precision casting production. Such products require smooth closed flow channels to reduce the resistance to fluid flow within the flow channels. To achieve this, the conventional production method is to make an integral wax pattern, ensure that there is no defect in the closed runner, and then try to form a complete shell in the closed runner, and have no casting defect after the pouring is completed, so as to ensure the qualified product quality.

As shown in fig. 1, a typical impeller with a closed structure is made of 304 stainless steel, and when the narrowest position of a flow channel is only 3.99mm, it is very difficult to meet 3 conditions for qualified product quality, and particularly, if any one of the three aspects of a wax mold, a shell and a casting is in a problem, the problem cannot be repaired, and finally, the impeller can only be scrapped, and the loss is very large. The conventional production method is adopted for production at present, and the yield is less than 15%.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides the production method of the closed impeller, which has low production difficulty and high yield and greatly reduces the production cost of the closed impeller.

The invention is realized by the following technical scheme:

the production method of the closed impeller comprises the following steps:

s1, dividing the impeller into an impeller body and an upper runner cover, wherein the number of the upper runner cover corresponds to that of the impeller body, and the impeller body with an open runner part and the upper runner cover matched with the open runner part are obtained by respectively and independently processing;

s2, processing the matching contour of the upper cover part of the corresponding missing flow channel on the impeller body, and making the size of the matching contour smaller than that of the upper cover of the flow channel processed in S2;

s3, respectively carrying out interference fit on the upper covers of the flow channels processed in the S1 at the corresponding fit contours on the impeller body in the S2;

and S4, processing a welding groove at the matching contour part of the previous step, and welding the impeller body and each flow channel upper cover into a whole through the welding groove.

This scheme will seal the impeller and divide into impeller body and runner upper cover two parts, and the runner position on the impeller body that removes the runner upper cover is open, and the casting degree of difficulty reduces to because be open runner, the operation of each link is very simple in the production process, also all very easily repaiies the defect that appears. The size and the shape of the part of the upper cover removed are precisely designed, and the corners are designed with round corners. Although the shape of the runner upper cover is irregular, the runner upper cover with qualified size can be completely and easily machined by using the machining center, the machined runner upper cover and the impeller body are welded in a combined mode, the manufactured product is the same as that manufactured by integral casting, and leakage risk does not exist.

Further, in step S2, corners of the mating profile are each rounded.

Furthermore, the size difference between the flow channel upper cover processed in the step S2 and the matching contour is 0.02-0.05 mm.

The invention has the beneficial effects that:

firstly, the production cost is greatly reduced, and although the processing and welding cost is increased, the production cost is also greatly reduced compared with the waste product of 85 percent.

And secondly, the production difficulty is low, the yield is high, and waste products are hardly generated in the production process. The impeller body part is convenient to cast, the quality of a flow channel can be completely guaranteed, the upper cover of the flow channel directly uses a steel plate, the price is low, the quality is better guaranteed, and the quality of the flow channel can be completely guaranteed.

And thirdly, the interference fit is adopted to ensure that the welding part has no clearance, the automatic welding technology is adopted to ensure the welding quality, and the manufactured product is the same as the product manufactured by integral casting without leakage risk.

Drawings

FIG. 1 is a schematic diagram illustrating the construction of a typical closed impeller structure as mentioned in the background of the invention;

FIG. 2 is a top view of FIG. 1;

FIG. 3 is a schematic structural view of a body portion of an impeller;

fig. 4 is a schematic structural view of an upper cover portion of a flow channel.

Shown in the figure:

1. the closed impeller comprises an enclosed impeller body 2, an impeller body 3, a flow passage 4 and a flow passage upper cover.

Detailed Description

In order to clearly illustrate the technical features of the present solution, the present solution is explained below by way of specific embodiments.

A production method of a closed impeller is characterized in that a product is divided into two independent parts, namely an impeller body 2 and a runner upper cover 4, which are respectively and independently produced and finally combined and welded together to form a closed impeller 1 product. The runner upper cover 4 is a cover plate above each runner 3 on the impeller body 2, and the number of the runner upper cover is equal to the number of the runners 3 correspondingly.

The method comprises the following steps:

s1, dividing the impeller 1 into an impeller body 2 and a runner upper cover 4, where the number of the runner upper cover 4 corresponds to the number of runners 3 of the impeller body 2, and separately processing the impeller body 2 (as shown in fig. 2) with open runner 3 and the runner upper cover 4 (as shown in fig. 3) matching with the open runner 3, where the runner upper cover 4 is generally made of steel plate, and the thickness of the steel plate is consistent with the thickness of the runner upper cover 4 of the impeller 1 to be processed, and although the shape of the runner upper cover 4 is irregular, the runner upper cover 4 with qualified size can be easily processed by using a processing center. As shown in fig. 1, four pieces of the runner upper cover 4 are required to be processed.

S2, processing the matching contour of the part of the impeller body 2 corresponding to the missing runner upper cover 4, considering convenient processing when designing the matching contour, designing round angles at each corner part, and easily processing the matching contour according with the size by using a processing center. In step S2, corners of the mating contour are each rounded.

The size of the matched contour can be accurately designed, and an electronic version drawing is formed, and the electronic version drawing can be directly used for programming a driving program on a machining center. The fitting contour size here is smaller than the size of the runner cap 4 machined in S2. Namely, the matching contour of the S2 is shifted to the inner side by 0.02-0.05 mm.

And S3, respectively carrying out interference fit on each flow channel upper cover 4 processed in the S1 at the corresponding fit contour on the impeller body 2 in the S2.

And S4, processing a welding groove at the matching contour part of the previous step, and welding the impeller body 2 and each flow channel upper cover 4 into a whole through the welding groove. Because the welding groove is machined by using a machining center and has very accurate shape and position, an automatic welding machine can be used for welding.

Of course, the above description is not limited to the above examples, and the undescribed technical features of the present invention can be implemented by or using the prior art, and will not be described herein again; the above embodiments and drawings are only for illustrating the technical solutions of the present invention and not for limiting the present invention, and the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that changes, modifications, additions or substitutions within the spirit and scope of the present invention may be made by those skilled in the art without departing from the spirit of the present invention, and shall also fall within the scope of the claims of the present invention.

Claims

1. A production method of a closed impeller is characterized in that: the method comprises the following steps:

2. The production method of a closed-type impeller according to claim 1, characterized in that: in step S2, corners of the mating contour are each rounded.

3. The production method of a closed-type impeller according to claim 1, characterized in that: the size difference between the flow channel upper cover processed in the S2 and the matching contour is 0.02-0.05 mm.