CN102395788A

CN102395788A - Piston pump having cam drive, particularly a fuel pump

Info

Publication number: CN102395788A
Application number: CN2010800170002A
Authority: CN
Inventors: F·伯金
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2009-04-16
Filing date: 2010-02-17
Publication date: 2012-03-28
Anticipated expiration: 2030-02-17
Also published as: EP2419635B1; DE102009002434A1; EP2419635A1; WO2010118903A1; CN102395788B

Abstract

The invention relates to a piston pump (10), particularly a fuel pump, having a shaft (12), at least one cam (14) arranged thereon, a piston, and a roller (20) arranged between the piston and the cam (14) for rolling on the cam (14), wherein on at least one face of the cam (14), an undercut-like recess (16) is provided.

Description

Have the reciprocating pump of cam driving gear, especially petrolift

Technical field

The present invention relates to a kind of according to claim 1 reciprocating pump as described in the preamble, especially petrolift.

Background technique

The petrolift of internal-combustion engine is known by market, and they are constructed to reciprocating pump and operate through cam driving gear.In some internal-combustion engines of Motor Vehicle, petrolift also is constructed to so-called " plug-in pump ".As plug-in pump, pump module is inserted in the opening in the cluster engine of internal-combustion engine for example.A kind of mode of execution has been described in DE 10 2,006 045 933, one of them in the roller supports that connects between cam and the piston in the rolling boots.For tolerance compensating, the rolling boots of pair of rollers guiding can be supported a little obliquely, thereby avoid corner angle to support, and that is to say the excessive pressure loading of having avoided on the seamed edge of the shell surface of cam and end face.

Summary of the invention

Task of the present invention is, improves the operation of petrolift, especially prolongs the working life of petrolift.

This task is through the device solves according to claim 1.Favourable expanded configuration provides in the dependent claims.To the important characteristic of the present invention in addition in below the specification and find in the accompanying drawings, wherein, these characteristics need not to spell out once more not only individually but also to be various combination ground possibly be important for the purpose of the present invention for this reason.

Because the manufacturing inaccuracy of roller or cam; Perhaps because the spin axis of the axle of roller and supporting cam wheel is not just in time parallel; Possibly in the zone of the radially-outer surface of cam, at first form high pressure stress on the edge at cam; These high pressure stress are not having to cause so-called " corner angle support ", i.e. the indenture shape in the cam outer face or the Roughness of angular under the situation of counter-measure.Avoid or reduced at least significantly the formation of such corner angle support through measure according to the present invention.Because the tolerance of the reason that the formation corner angle support is very little mostly, be the heavy corresponding little and local effectively adaptive compensation that enough is used for of cutting the dead slot form of shape (freistichartig) at least one end face of cam arranged according to the present invention.At this, utilize the elasticity of employed metallic material, especially steel to reduce in the lateral edge region generating rigidity of cam.Even we can say, can in the zone of cam seamed edge, produce to a certain degree " deformability of spring " according to the present invention with respect to roller.Therefore need and not make cam wideer for fear of the corner angle support.In this way, the inexactness that in the cooperatively interacting of roller and cam, is caused by manufacturing is not damaged the fatigue strength of reciprocating pump to a great extent.Therefore, the working life of reciprocating pump, raising and its operation improved.

Suggestion in addition, the heavy dead slot that cuts shape radially inwardly extends the radially-outer surface up to axle.Save quality thus, and can simplify heavy manufacturing of cutting the dead slot of shape.

Another kind of design proposal is that the heavy dead slot that cuts shape has a cross section rectangle, trapezoidal or circle.Can make the heavy rigidity of cutting the generation of shape dead slot of passing through in cam lateral edge zone reduce optimally suitable through differing formed cross section with the certain loads situation of reciprocating pump.The heavy rectangular cross section that cuts the dead slot of shape can be made at this especially simply.When the trapezoidal cross-section of the heavy dead slot that cuts shape, rigidity reduce substantial linear ground axle vertically on change, thereby although stress peak can be reduced when manufacturability is simple.Best fatigue strength realizes through (for example circular or oval-shaped) of circle or the cross section of strong rounding, because especially when violent dynamic load, avoided high pressure stress or tensile stress in the zone of the heavy dead slot that cuts shape.

The present invention stipulates that cam configuration is single cam, double-cam or three cams in addition, although also can realize having the reciprocating pump of high transmission power thus in working life under the good situation.

Another kind of design proposal is that the heavy dead slot that cuts shape only is arranged in the part area of said end face.Can consider that thus according to the angle of swing of cam, different power and loading are on cam or roller.Through this design proposal can make heavy geometrical shape of cutting the dead slot of shape optimally adapt to the angle of swing of cam and the work with driven reciprocating pump of optimally adapting to than corresponding load.

A kind of specially suitable application scenarios of the present invention is a plug-in pump, and they can be inserted in the opening of the drive unit housing of internal-combustion engine for example.Such plug-in pump is applied in the internal-combustion engine of Motor Vehicle and is a kind of with low cost and solution flexibly.

Description of drawings

Set forth exemplary mode of execution of the present invention with reference to the accompanying drawings.Use identical reference character at this assembly with parameter for function equivalent.Shown in the drawings:

Fig. 1 has the partial sectional view of part area of reciprocating pump first mode of execution of single cam;

Fig. 2 has the partial sectional view of the part area of two-jawed reciprocating pump second mode of execution;

Fig. 3 has the sectional view of live axle of reciprocating pump the 3rd mode of execution of single cam;

Fig. 4 has a single cam and the heavy partial, longitudinal cross-sectional of cutting the axle of shape dead slot with rectangular cross section in this list cam face;

Fig. 5 is similar to the heavy view that cuts the shape dead slot with trapezoidal cross-section in single cam face that has of Fig. 4;

Fig. 6 is similar to the heavy view that cuts the shape dead slot with circle cross-section in single cam face that has of Fig. 4.

Embodiment

Fig. 1 illustrates the part of reciprocating pump 10 with phantom, like it using in the internal-combustion engine of Motor Vehicle.Be arranged on prejudicially on this axle at 12, one cams 14 of a cut in the axial direction axle shown in the part of the bottom of this figure, this cam has the cross section of a circular.In the observer's of Fig. 1 end face, process a heavy dead slot 16 that cuts shape at this cam 14; This dead slot sees to have small depth on the axial direction of axle 12, in this end face of cam 14 and the transition region between the radially-outer surface, form an axially extended dividing plate 18 through this dead slot.Opposed end face is likewise constructed.In Fig. 1, above cam 14, be provided with a columniform roller 20, this roller is along a common bus contact cam 14.Roller 20 has roughly suitable with the width of cam 14 axial length, and this roller leads in rolling boots 22 with the one of which semi-circumference approximately.These rolling boots 22 are directed to sleeve 24 and keep, and this pilot sleeve has the hollow cylinder shape that both sides are opened wide basically.Helical spring 26 acts on one and in Fig. 1, is arranged on above the dividing plate on pilot sleeve 24 underparts, that radially extend.A piston 28 is supported on these rolling boots 22, and this piston is directed in a housing 30 movably, and another end portion, supports of helical spring 26 is on this housing.Pilot sleeve 24 is columniform and go up guiding with piston 28 concentric convexities (not having reference character) of housing 30.Hole 32 in the housing 30 can be implemented in during the piston motion being enclosed in the pressure compensation in the space between rolling boots 22, pilot sleeve 24, housing 30 and the piston 28.

Be in operation, the cycle that the eccentric motion of cam 14 is responsible for piston 28 drives.Roller 20 causes the power transmission of the low wearing and tearing of cam 14 to rolling boots 22 at this.At this, roller 20 continuously and low frictionally on the radially-outer surface of cam 14, roll, and roller 20 is supported in rolling boots 22 slidably.At this, from the lower dead centre shown in Fig. 1, helical spring 26 is compressed simultaneously.After the unshowned upper dead center switching-over from, the helical spring 26 of expansion causes the joint of the force closure of rolling boots 22, roller 20 and cam 14 during moving downward.

Realize that through the heavy dead slot 16 that cuts shape local rigidity reduces, roller 20 is only still supported by dividing plate 18 in the fringe region of the side direction of cam 14.Through the rigidity that reduces, the fringe region of this side direction can be made a concession when between cam 14 and roller 20, parallelism error occurring, avoids forming so-called corner angle thus and supports, be i.e. the Roughness of corrugated in the surface of cam 14 and/or angular.

Fig. 2 illustrates the sectional view of the part of second mode of execution with oval two-jawed reciprocating pump 10.Also see a heavy dead slot 16 and a dividing plate 18 that forms thus that cuts shape in observer's the end face at cam 14 here.According to one measured in the circumferential direction and characterize the geometry of the cam 14 angle apparently undercut empty slot 16 has a shape and angle

related to the size of 34.A size 36 that equally also can be dividing plate 18 is relevant with angle

.

During the revolution that is configured to two-jawed cam 14, obtain two complete work tempos of reciprocating pump 10 and frequency of okperation is doubled with respect to the operation of single cam.

Fig. 3 illustrate have one different with Fig. 1 be not circular but the sectional view of the live axle 12 of reciprocating pump 10 the 3rd mode of execution of single cam 14 of substantially elliptical.Cam 14 carries out the transition to the round-shaped of axle 12 in its bottom part in Fig. 3.The top part of cam 14 comprises the heavy dividing plate 18 that cuts the dead slot 16 of shape and form thus again.

During the revolution of cam 14, obtain the complete work tempo of reciprocating pump 10.

Fig. 4 illustrates the side view of axle 12 together with the partly cut-away of cam 14, and this cam configuration is single cam and unit current and an integral body of axle 12 formation.A roller 20 is shown above cam 14, and this roller has a forming section radial symmetric, convex surface (not being with reference character) on two end faces.Can find out the not only heavy cross section that cuts the dead slot 16 of shape but also have rectangle through the dividing plate 18 that the heavy dead slot 16 that cuts shape forms.

Axle 12 is shown the similar Fig. 4 of Fig. 5 together with the cam 14 and the side view that is bearing in the partly cut-away of the roller 20 on the cam 14 that are arranged on the axle.At this, the heavy dead slot 16 that cuts shape has trapezoidal cross section respectively with dividing plate 18.

Axle 12 is shown the similar Figure 4 and 5 of Fig. 6 together with the cam 14 and the side view that is bearing in the partly cut-away of the roller 20 on the cam 14 that are arranged on the axle.At this, the heavy dividing plate 18 that cuts the dead slot 16 of shape and form thus has the cross section of strong rounding.

What can expect in addition is that irrelevant with the embodiment of cam, additional ground or conversion ground are provided with a heavy dead slot that cuts shape with respective action on roller 20, support to avoid corner angle.

Claims

1. reciprocating pump (10), especially petrolift; Comprise an axle (12), at least one is arranged on cam (14) on this, piston and one and is arranged on being used between piston and the cam (14) and goes up the roller (20) that rolls at this cam (14); It is characterized in that, at least one end face of this cam (14), be provided with the heavy dead slot (16) that cuts shape.

2. reciprocating pump according to claim 1 (10) is characterized in that, the said heavy dead slot (16) that cuts shape radially inwardly extends the radially-outer surface up to said axle (12).

3. according to each described reciprocating pump (10) in the above claim, it is characterized in that the said heavy dead slot (16) that cuts shape has cross section rectangle, trapezoidal or circle.

4. according to each described reciprocating pump (10) in the above claim, it is characterized in that said cam (14) is configured to single cam, double-cam or three cams.

5. according to each described reciprocating pump (10) in the above claim, it is characterized in that the said heavy dead slot (16) that cuts shape only exists in a part area of said end face.

6. according to each described reciprocating pump (10) in the above claim, it is characterized in that said reciprocating pump is a plug-in pump, this plug-in pump can be inserted in the opening of actuator housing.