JPH08281343A - Tubular housing especially for fuel pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an improved pump housing manufactured with a simple method without being machined. SOLUTION: In a tubular housing for a pump, motor or the like, especially a fuel pump wherein a step 5 or 6 expanding the inside diameter Di of the housing 1 with the outside diameter DA kept constant in order to keep the bearing shield of e.g. a pump motor airtight is formed in the inner wall of the housing 1, the housing 1 is manufactured by deep drawing as a deforming technique without being machined from a circular shape 7. At this time, the step 5 or 6 is formed by expansion drawing via an inside mandrel 12 corresponding to the shape and dimension of the step.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an inner wall of a housing,
For example, the present invention relates to a tubular housing for a pump, a motor, etc., in particular, a fuel pump, in which a step is formed to increase the inner diameter of the housing while keeping the outer diameter constant in order to keep the bearing shield of the pump motor tight. The invention further relates to a method of manufacturing such a tubular housing, in particular for a fuel pump.

[0002]

BACKGROUND OF THE INVENTION Fuel pumps, and also motors, are often housed in one-piece tubular housings, which are open-ended cylindrical, so that, for example, pump cylinders, valve blocks, spring elements and motors. Pump components and electrical connections to be housed within the housing, such as
Liquid conduits and mechanical connections can be easily inserted and fixed. At that time, the well-known tubular housing is
On its inner wall there is a step on both open sides in order to keep the bearing shield of the pump cylinder tight, for example. Such pump housings are manufactured from welded tubing cut to length, the subsequent cutting process forming a step on each side and providing the desired surface quality and dimensions. Manufactured. This is associated with a number of manufacturing costs, which considerably impair the economics and marketability of such pump housings. It is an industrial disadvantage that the leaktight construction of the housing is seldom leak-proof and that this leads to increased waste. The precision and shape and position tolerances that can be achieved by subsequent cutting also need to be improved, which means that for example the edge radius of the steps required for the desired degree of tightness is in a new condition by lathe turning. It is clear that it can be manufactured only when using. The double function of the step, ie the retention and sealing of the pump part adjoining it, is ensured only by tedious processing and inspection.

In summary, it can be seen that the known housings and their manufacturing methods need to be improved technically and economically due to the drawbacks caused by the use of welded pipes and subsequent cutting operations. A large number of successive processing steps have to be carried out and high mechanical costs are required.

[0004]

In view of this prior art, it is the object of the present invention to provide an improved pump housing which avoids the abovementioned disadvantages and which can be manufactured in a simple manner without machining. is there.

[0005]

According to the present invention, this problem is solved as follows. That is, the housing is a deep-drawn part manufactured without being cut from a circular shape by deep drawing as a deformation technique, in which the step is formed by an expansion throttle (Abstr) through an inner mandrel corresponding to the shape and size of the step.
ckziehen). This makes it possible, in a very simple manner, to produce inner steps and surface qualities with the same outer diameter from end to end with a very high degree of accuracy, without cutting, and for example in the advantageous construction the desired R <0. It is achieved that there is no problem setting an inner diameter of 0.2 mm and an edge chamfer with an angle of approximately 30 ° without additional processing steps. According to the invention, the pump housing, which is present as a deep-drawing part, has a partial cost which is still only 1/3 of that of the prior art, which is of great economic advantage, in which case there is no welding seam. The technical quality is significantly improved because there is no need to anticipate leaks and the manufacturing accuracy is increased.

According to an advantageous construction, the deep-drawn part is a cylinder open on both sides, which cylinders are formed according to the invention with a certain distance on each open side. It has a step. In that case, the outer diameter remains the same, but the wall thickness is reduced in the step region by enlarging the inner diameter with respect to the central part of the housing. In that case, low shape and position tolerances and low achievable roughness depths are advantageously achieved in comparison with the prior art, and finally due to the manufacturing, particularly during the handling of the pump housing and thus especially the plating. A material reinforcement is achieved which makes it less susceptible to damage during post-treatment or during transport.

With respect to the method, according to the present invention, the tubular pump housing is manufactured as follows. That is, abandoning the conventional method mode, in the first method step, a pot-shaped hollow member is formed from a metal circle by deep drawing or pressing in multiple steps, and in the second method step, the hollow member is opened. The edge of the side is spread out,
And in order to prepare a hollow cylinder open on both sides, the bottom of the pot is removed, and then the inner mandrel is inserted into the enlarged part, which is the stage to be manufactured without cutting for shape, size and surface. The steps on the inner wall of the combined and hollow cylinder are produced by a multi-step expansion drawing through the inner mandrel, and finally the inner mandrel is removed, and the housing is optionally cut to length. To be done. Before cutting to the prescribed length as much as possible,
The second open side of the hollow cylinder is also unrolled and another step in the inner wall of the hollow cylinder is formed by a multi-step expansion stop through the inner mandrel.

Advantageously, in the region of the enlargement, just enough material is available for the subsequent expansion drawing in order to be able to produce steps of the desired length and wall thickness without subsequent processing. At that time, a deformation degree of about 50% is set. The enlarged portion is formed in a V shape as much as possible, but it should be pointed out that it is basically possible to enlarge at a right angle.

[0009]

Further details, features and advantages of the subject matter of the invention are apparent from the following description of the associated drawing, which schematically shows the pump housing and the various method steps for its manufacture.

The tubular housing 1 of the fuel pump shown in FIGS. 1 to 3 of the drawings is a hollow cylinder open on both sides of a circular cross section, which hollow cylinder has the same outside diameter DA from end to end. . The housing 1 consists of a central part 2 which transitions on either side into a step area 3 or 4, which step area is shown in an enlarged view in FIGS. 2 and 3 of the drawings. The inner diameter DI of the central range is D in the step range 3 or 4
The intermediate value DZ, which lies between A and DI, is increased, and the wall thickness in the step region 3 or 4 is correspondingly reduced to approximately half the wall thickness of the central part 2.

FIGS. 2 and 3, which include the details Y and X in an enlarged representation, show the step ranges 3 and 4, and in particular the steps 5 and 6 provided adjacent to the open side of the housing 1.
It is revealed that it is produced at right angles from the inner wall of the housing 1, in which case the bearing shield for the fuel pump part, which is in contact with the stages 5, 6 in the completed state and is pressed, is provided without additional sealing means. The inner radius R must be maintained at a maximum of 0.2 mm in order to keep it tight. Furthermore, it is clear that the transition edge to the central part 2 is chamfered at an angle of approximately 30 °.

The manufacture of the housing is carried out by various method steps, as shown in FIGS. 4 and 5 of the drawings. In this case, by starting from the material circle 7 and thus from a flat circular plate part and then applying deep drawing as a deformation technique, a pot-shaped hollow member as shown in FIG. 4 (1) is formed. . The deep drawing is carried out in a manner known per se so that the circle 7 is drawn by the preceding stamper and the drawing tool and in this way a container is formed, the diameter of the circle being between the deep drawing. , (As shown in the drawing)
It constantly decreases from the initial diameter and reaches the stamper diameter towards the end of the drawing process. The throttling is carried out in several stages, the process being clear from FIG. 4 (2).

In the next method step, the open edge of the pot-shaped hollow member 8 is then expanded outwardly (tulip-shaped), as shown in FIG. 4 (3) of the drawing, depending on the drawing. In the preferred embodiment, a V-shape is selected for the tulip / amplification 9. The pot bottom 10 is subsequently removed by drilling to form an open sleeve 11 on both sides according to FIG. 4 (4) of the drawing. Due to this deep drawing process in the steps up to this method step, it can be assumed that the material thickness in the center does not change and thus the surface areas of the initial circle 7 and the sleeve 11 are approximately the same size. .
The material has already been strengthened on the basis of the deformation.

Subsequent processing is carried out only in the deep-drawing deformation process on the re-strike, using the pre-squeezed sleeve 11 on striking as the initial form instead of a flat cutting piece. The setting of the goal then consists in simply forming the steps 5 and 6, in which case
The constricted portion is thereby brought to its final length at the same time. The process of deep drawing in re-strike is well known to be performed in a plurality of steps as much as possible, and is also referred to as expansion drawing. The inner mandrel 12 is then inserted from below into the tulip-shaped part 9 as shown in FIG. 5 (1) of the drawing, or the sleeve 11 is placed over such an inner mandrel. It has a pin 13 and a stamper part 14 which are matched in shape, size and surface to the step 5 or 6 to be produced without cutting and thereby project into the sleeve 11. The pin 13 has an outer diameter tuned to the inner diameter DI of the sleeve 11, while the stamper 14 is
It has a diameter corresponding to the inner diameter DZ in the step range of the completed housing 1. Due to the shape, dimensions and surface, the inner mandrel 12 is tuned to the stage range 3 or 4 to be produced in the subsequent drawing process. At the same time as the reduction (not shown), the subsequent deformation is performed in a plurality of steps.
FIG. 5 (2) shows the result. The step 5 now formed on one side of the sleeve 11 is apparent.

The second step 6 is also formed on the opposite side of the sleeve 11, so that the above-mentioned method steps are repeated here and the tulip-shaped 15 into a V-shape is carried out and is completed according to FIG. 5 (4). In order to produce a customized housing, the expansion drawing process is repeated, as shown in FIG. 5 (3), which housing has on both open sides thereof the desired step area 3 as shown in FIG. 1 of the drawings. And 4.

It is self-evident that the diameter reduction achievable during stepwise deformation in the working process depends on the material, the lubrication, the shape of the tool and whether the material is incandescent or not after impact. , And therefore not explained in detail. Although starting from a metal / steel circle in the above description, it is also possible to manufacture the housing from synthetic material by mechanical deep drawing.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a fuel pump housing.

FIG. 2 is an enlarged view showing a portion “Y” of the fuel pump housing of FIG.

FIG. 3 is an enlarged view showing a portion “X” of the fuel pump housing of FIG. 1.

FIG. 4 is a schematic representation of the step-by-step manufacture of the fuel pump housing according to FIG.

5 is a schematic representation of the step-by-step manufacture of the fuel pump housing according to FIG.

[Explanation of symbols]

 1 Housing 5 steps 6 steps 7 Circular 12 Inner mandrel

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Rudolf Rutzten Federal Republic of Germany Solingen Theodor-Montmuzen-Schutlerse 28

Claims (8)

[Claims] 1. An outer diameter (D) for tightly holding a bearing shield of, for example, a pump motor on an inner wall of the housing.
The inner diameter (D) of the housing (1) while keeping A) constant
In tubular housings for pumps, motors, etc., especially fuel pumps, in which a step (5 or 6) enlarging I) is formed, the housing (1) is cut from a circle (7) by deep drawing as a deformation technique. Without a deep drawing, characterized in that the step (5 or 6) is formed by an expansion drawing through an inner mandrel (12) corresponding to the shape and size of the step. , Especially tubular housings for fuel pumps. 2. The deep drawing part is a cylinder (sleeve 11) which is open on both sides, the cylinder being a step (5 and 6) formed by an expansion draw with a certain distance on each open side. A housing according to claim 1, characterized in that 3. One or more stages (5 or 6) have R <
Housing according to claims 1 and 2, characterized in that it has an inner radius of 0.2 mm and has an edge chamfer at an angle of approximately 30 °. 4. A constant outer diameter (DA) and an enlarged inner diameter (D) with decreasing wall thickness in the step range (3 and 4).
Housing according to one of claims 1 to 3, characterized in that it has an inner diameter (DI) which is widened to Z). 5. In a first method step, a pot-shaped hollow member (8) is formed from a metal circle (7) by multiple steps of deep drawing or pressing, and in a second method step, the hollow member (8). ) The open edge is widened outwards (expansion 9) and the bottom of the pot (10) is removed to prepare a hollow cylinder (sleeve 11) open on both sides, expanding (9) An inner mandrel (12) is inserted therein, which inner mandrel is aligned with the step (5) to be produced without cutting in shape, size and surface and on the inner wall of the hollow cylinder (11) ( 5) is the inner mandrel (1
Characterized in that it is manufactured by multi-step expansion drawing via 2) and finally the inner mandrel (12) is removed and the housing (1) is optionally cut to length. 5. A method for manufacturing a tubular housing according to claim 1, in particular a fuel pump housing. 6. The second open side of the hollow cylinder (sleeve 11) is also widened (enlargement 15) and the second step (6) on the inner wall of the hollow cylinder is provided with an inner mandrel (12). Method according to claim 5, characterized in that it is formed by a multi-step expansion diaphragm. 7. In the area of the enlargement (9 or 15), just enough for a subsequent expansion stop to produce a step (5 or 6) of the desired length and wall thickness without subsequent processing. 7. A method as claimed in claims 5 and 6, characterized in that different material quantities are provided, with a degree of deformation of approximately 50% being set. 8. The method as claimed in claim 5, wherein the widening (9 or 15) is V-shaped.