DE102015105068A1 - pump - Google Patents

Abstract

A cylindrical guide (30) is arranged in a housing opening (111) and arranged on an outer circumference of a plunger (172) and a plunger spring (18). When a plunger piston (17) breaks and the plunger (172) breaks off in a sliding direction A, the guide (30) is adjacent to a housing-opening inner wall (112) and restricts a range of movement of the guide (30) and Tappet (172) in the sliding direction A. Accordingly, the plunger (172) is prevented from penetrating into a gap between a housing body (11) and a cam ring (16), and thus damage to the housing body (11) is prevented.

Description

TECHNICAL AREA

The present disclosure relates to a pump that pumps a fluid by converting rotational motion of a cam ring into reciprocation of a plunger.

BACKGROUND OF THE INVENTION

These types of pumps are conventionally z. B. in the JP 2005-113807A described. The in the JP 2005-113807A described pump includes a plunger, which is formed of a disc-shaped plunger and a cylindrical plunger body. In addition, a cam ring rotates a camshaft without rotating. The plunger slides on a sliding surface of the cam ring and the plunger reciprocates. Accordingly, the plunger piston body pumps the fuel.

However, if the fuel accidentally z. As water is added, it is possible to insufficient lubrication of the plunger, which can thereby seize. At the same time, the cam ring continues its orbital motion and, as a result, can exert an excessively high compressive force on the plunger, resulting in rupture of the plunger. When a portion of the plunger such. As the plunger, breaks off and penetrates into a gap between the cam ring and a housing of the pump, thereby the housing can be damaged.

SHORT VERSION

It is an object of the present disclosure, in view of the above-mentioned problem, to prevent damage to the housing when the plunger piston has broken.

According to the present disclosure, there is provided a pump comprising: a camshaft that rotates, a cam that is eccentrically disposed with respect to the camshaft, the cam rotates integrally with the camshaft, a cam ring disposed on an outer circumference of the cam and rotates the camshaft without rotating, the cam ring including a cam ring sliding surface; a plunger including a plunger sliding surface sliding on the cam ring sliding surface in a sliding direction while the cam ring performs its orbiting motion; wherein the plunger is disc-shaped and, when the cam ring performs its orbital motion, reciprocates in a direction perpendicular to the cam-ring sliding surface, a plunger-piston body formed integrally with the plunger, wherein the plunger-piston body with the plunger reciprocates to pump a fluid, a A housing surrounding the cam ring and the plunger and having an opening therein, wherein the opening has an inner wall, and a guide which is disposed within the opening and is secured to an outer periphery of the plunger, wherein the guide, together with the plunger, reciprocating along the inner wall of the opening, where a range of movement of the guide in the sliding direction is restricted by the inner wall of the opening.

Even if the plunger piston is broken, a range of movement of the guide and the plunger is accordingly restricted by the housing. That is, it is prevented that the plunger penetrates into the gap between the housing and the cam ring, whereby damage to the housing is prevented.

BRIEF DESCRIPTION OF THE DRAWING

The drawing described herein is for illustrative purposes only and is not intended to limit the scope of the present disclosure in any way.

1 FIG. 10 is a front cross-sectional view of a pump according to a first embodiment of the present disclosure. FIG.

2 FIG. 15 is a perspective view of a plunger and a guide for the pump according to the first embodiment. FIG.

3 FIG. 12 is a perspective view of a guide showing a first modified example of the first embodiment. FIG.

4 FIG. 13 is a perspective view of a guide for a pump according to a second embodiment of the present disclosure. FIG.

5 Fig. 16 is a perspective view of a guide showing a first modified example of the second embodiment.

6 Fig. 15 is a perspective view of a guide showing a second modified example of the second embodiment.

7 FIG. 12 is a perspective view of a guide for a pump according to a third embodiment of the present disclosure. FIG.

8th is a view that the form of leadership of 7 as viewed from an axial direction.

9 Fig. 15 is a perspective view of a guide showing a first modified example of the third embodiment.

DETAILED DESCRIPTION

Hereinafter, the embodiments of the present disclosure will be described with reference to the drawings. In addition, elements which are identical or equivalent to one another from embodiment to embodiment are identified by the same reference sign.

First Embodiment

In a first embodiment of the present disclosure, a pump for pressurizing and supplying fuel to a high pressure fuel pressure accumulator common rail is provided. The common rail is used in an accumulator type fuel injection device for an internal combustion engine (particularly, a compression ignition type internal combustion engine).

As in 1 is shown, a housing for the pump includes an aluminum housing body 11 and a pair of ferrous metal cylinder heads 12 , A cam chamber 13 is inside the housing body 11 formed, and a feed pump (not shown), the fuel of the cam chamber 13 to.

At each end of the case body 11 is a housing opening 111 formed as a cylindrical cavity. An area of a respective cylinder head 12 is in a respective one of the housing openings 111 inserted so that the cam chamber 13 is included. In addition, the cam chamber 13 connected to a fuel tank (not shown).

A camshaft made of iron metal 14 is through the housing body 11 rotatably mounted. The camshaft 14 is driven by an internal combustion engine (not shown), thereby rotating. A cam 15 with a circular cross-section is integral with the camshaft 14 formed so that it rotates integrally with the same. In addition, the cam is 15 in relation to the camshaft 14 arranged eccentrically.

A cam ring 16 is on an outer circumference of the cam 15 fitted and rotates the camshaft 14 , The cam ring 16 includes a cam ring body 161 and a socket 162 integral with the cam ring body 161 is trained. In particular, the cam ring body 161 formed of ferrous metal, has the shape of a quadrangular column on the outside and includes a circular through hole. The socket 162 is a cylinder formed of metal (eg, copper, aluminum, iron, and the like) or resin, and becomes the through hole of the cam ring body 161 press-fit. In terms of the cam 15 rotates the socket 162 free. An outer circumference of the cam ring body 162 includes two cam ring sliding surfaces 163 that with the plunger pistons 17 , which are described below, slidably engage.

On each side of the cam ring 16 is a plunger made of iron metal 17 arranged so that it revolves the cam ring 16 follows and thus moves back and forth. Each of these plunger pistons 17 includes a cylindrical plunger body 171 and a discoidal (disc-shaped) plunger 172 , The plunger body 171 is within an inner cylinder area of each of the cylinder heads 12 arranged so that it can move back and forth, and the plunger 172 is at one end of the plunger body 171 arranged. The pestle 172 includes a plunger sliding surface 173 attached to a respective one of the cam ring sliding surfaces 163 so adjoins that the plunger sliding surface 173 on the cam ring sliding surface 163 slides.

In addition, the cam 15 , the cam ring 16 and the pestles 172 inside the cam chamber 13 taken up and from the housing body 11 locked in.

Below are specific descriptions regarding one of the two plunger pistons 17 , in the 1 are shown. However, the descriptions thereof refer to both plunger pistons 17 , in the 1 are shown.

The plunger 17 will be in the direction of the cam ring 16 by a pusher spring 18 in the cam chamber 13 is arranged, biased, and the plunger 172 is against the cam ring 16 pressed. In addition, prevents abutment of the plunger sliding surface 173 on the cam ring sliding surface 163 that the cam ring 16 rotates. Accordingly, the cam ring rotates 16 not, but rather goes along with the rotation of the cam 15 a circular motion while he is in relation to the plunger 172 performs a sliding movement.

When the cam ring 16 performs its orbital motion, the cam ring move 16 and the plunger 17 relative to one another in a direction A. The direction A is parallel to the plunger sliding surface 173 and the cam ring sliding surface 163 and is perpendicular to an axis of the camshaft 14 , The direction A is in 1 as the left-to-right direction is hereinafter referred to as a sliding direction A.

When the cam ring 16 In addition, the plunger moves 17 in a direction perpendicular to the plunger sliding surface 173 and the cam ring sliding surface 163 (in 1 the top-down direction) back and forth.

Inside the cylinder head 12 is a fuel pressurization chamber 19 , which receives the fuel from a feed pump, at one end of the plunger body 171 (opposite the ram end) arranged. In addition, an entry check valve 20 and an exit check valve 21 inside the cylinder head 12 arranged. The inlet check valve 20 only allows the flow of fuel from the feed pump to the fuel pressurization chamber 19 , In addition, the exit check valve allows 21 only the flow of fuel from the fuel pressurization chamber 19 to a common rail (not shown).

As in the 1 and 2 is shown, is a cylindrical guide 30 inside the housing opening 111 arranged and on an outer circumference of the plunger 172 and the pusher spring 18 arranged. The leadership 30 can be formed by cutting a cylindrical metal line or by machining a metal rod.

The leadership 30 is with the pestle 172 assembled by press fitting and performs together with the same a reciprocating motion. Next to it is the guide 30 an axial dimension so that even if the plunger piston 17 at a bottom dead center (hereinafter referred to as UT), at least a portion of the guide 30 inside the housing opening 111 remains.

Furthermore, an outer diameter of the guide 30 set so that it is smaller than a diameter of the housing opening 111 is, leaving a gap between the leadership 30 and a housing opening inner wall 112 (Inner wall) of the housing opening 111 is defined. In other words, the leadership 30 in the sliding direction A adjacent to the housing-opening inner wall 112 , Thus, the lead leads 30 along the housing opening inner wall 112 a float. In addition, an inner diameter of the guide 30 set so that it is larger than an outer diameter of the plunger spring 18 , leaving a gap between the guide 30 and the pusher spring 18 is defined.

Subsequently, the operation of the pump will be explained. When the camshaft 14 is driven by the internal combustion engine, the camshaft rotates 14 and drives the feed pump. Accordingly, the feed pump sucks the fuel from the fuel tank, pressurizes and discharges the fuel. In addition, the cam rotates 15 along with the rotation of the camshaft 14 , The cam ring 16 does not rotate but rather leads with the rotation of the cam 15 an orbital motion. The plunger 17 moves along with the orbital motion of the cam ring 16 back and forth.

While the cam ring 16 performs its orbital motion, and when the plunger piston 17 At the top dead center (hereinafter referred to as TDC) and moving toward the BDC, the fuel discharged through the feed pump flows through the entry check valve 20 and in the fuel pressurization chamber 19 , When the plunger piston 17 reaches the UT and moves back to TDC, the entry check valve closes 20 and the fuel pressure in the fuel pressurization chamber 19 rises. When the fuel pressure in the fuel pressurization chamber 19 rises, the exit check valve opens 21 and the high pressure fuel is supplied to the common rail.

However, part of the fuel discharged through the feed pump flows into the cam chamber 13 , This fuel causes sliding portions of the cam 15 and the socket 162 and sliding portions of the cam ring body 161 and the pestle 172 (in other words, the cam ring sliding surface 163 and the plunger sliding surface 173 ) lubricated.

Here is the guide 30 adjacent to the housing opening inner wall 112 in the sliding direction A as described above. As a result of this positional relationship between the leadership 30 and the housing opening inner wall 112 show the lead 30 and the pestle 172 a restricted range of motion in the sliding direction A. In other words, a range of motion becomes the guidance 30 in the sliding direction A through the housing opening inner wall 112 limited. So if the plunger piston 17 to break and the pestle 172 breaks off, and the leadership 30 yourself together with the pestle 172 moves in the sliding direction A, a movement of the guide 30 and the pestle 172 restricted when the leadership 30 the housing opening inner wall 112 contacted. Accordingly, it prevents the plunger 172 in the gap between the housing body 11 and the cam ring 16 forced out. Thus, damage to the housing body 11 prevents and prevents fuel through the cam chamber 13 exit.

Even if the plunger piston 17 Breakage may, according to the present embodiment, damage to the housing body 11 be prevented.

Moreover, in the present embodiment, the guide 30 by cutting a cylindrical metal line or machining a metal rod. As in 3 however, in a first modified example of the first embodiment, the guide may be shown 30 also be formed by a metal plate is formed into a cylindrical shape. That way, the leadership 30 more easily than by cutting a cylindrical tube or machining a rod.

Second Embodiment

In a second embodiment of the present disclosure, the guide becomes 30 modified in the first embodiment. However, all the other elements are kept unchanged as in the first embodiment, so that in the description only elements that differ from the first embodiment will be discussed.

As in 4 is presented, becomes a guide 30 of the present embodiment, by bending a metal plate into a cylindrical shape. In addition, the guide includes 30 a wall surface having therein guide through holes 301 ,

A plurality of the guide through-hole 301 is along a circumferential direction of the guide 30 trained and near the center of the guide 30 positioned in an axial direction. In addition, the guide through holes 301 formed by press working the metal plate before the metal plate is curved.

Then, during operation, the pump can be inserted into the cam chamber 13 flowing fuel through the guide through holes 301 free in and out of the guide 30 pour out.

According to the present embodiment, the same effects as those according to the first embodiment can be obtained. Beyond that is the manufacture of the leadership 30 easy. In addition, by arranging the guide through holes 301 the fuel flow near the guide 30 be improved.

Moreover, in the present embodiment, the guide through holes are 301 near the center of the guide 30 positioned in the axial direction. As in 5 however, in a first modified example of the second embodiment, the guide through holes may be made 301 near the two ends of the guide 30 be arranged in the axial direction. As in 6 Further, in a second modified example of the second embodiment, the guide through-holes 301 near the center of the guide 30 as well as near the two ends of the guide 30 be arranged in the axial direction.

Third Embodiment

In a third embodiment of the present disclosure, the guide is 30 modified according to the first embodiment. However, all the other elements are kept unchanged as in the first embodiment, so that in the description only elements that differ from the first embodiment will be discussed.

As in 7 and 8th is shown, the leadership is 30 the present embodiment by drawing metal z. B. formed into a cylinder.

In particular, the leadership 30 when viewed from the axial direction of the guide 30 formed like a star-shaped polygon. In other words, the guide includes 30 a plurality of inner guide projections 302 pointing towards an inside of the guide 30 projecting inwardly, and a plurality of outer guide protrusions 303 that protrude outward. In addition, the inner guide protrusions 302 and the outer guide projections 303 along the circumferential direction of the guide 30 arranged alternately.

If then the leadership 30 with the pestle 172 is joined by press fitting (see 1 ), contact the front areas 304 the inner guide projections 302 the pestle 172 , In other words, contact the guide 30 and the pestle 172 each other at a plurality of positions along the circumferential direction of the guide 30 ,

If beyond the leadership 30 with the pestle 172 is assembled by press fitting, form between an inner surface of the guide 30 and the outer surface of the plunger 172 Cavities. These cavities serve as flow paths for the in the cam chamber 13 flowing fuel. Accordingly, a Fuel flow near the guide 30 be improved.

According to the present embodiment, the same effects as those of the first embodiment can be obtained. In addition, the leadership 30 formed like a star-shaped polygon and can thus be made more rigid than a cylindrical guide 30 , As well as the leadership 30 and the pestle 172 In point or linear contact, thereby reducing the force required for the press fit, and press-fitting operations can thus be performed easily. In addition, the serve between the inner surface of the guide 30 and the outer surface of the plunger 172 formed cavities as flow paths for in the cam chamber 13 flowing fuel, causing the fuel flow near the guide 30 can be improved.

Furthermore, in the present embodiment, the guide 30 formed like a star-shaped polygon. As in 9 however, in a first modified example of the third embodiment, a guide may be provided 30 a plurality of guide projections 306 pointing towards an inside of the guide 30 protrude inward, eliminating the guide projections 306 on a cylindrical guide body 305 are arranged.

Other Embodiments

In the respective embodiments described above, the guide 30 and the pestle 172 assembled by press fitting. The leadership 30 and the pestle 172 however, can be assembled by other methods than the interference fit.

In addition, the present disclosure is not limited to the above-described embodiments, but may be modified as appropriate.

Moreover, the respective embodiments described above are not unrelated to each other, and except for cases where a combination is clearly not possible, they can be suitably combined with each other.

Moreover, in the respective embodiments described above, constituents of the embodiments are not always essential unless the constituents are clearly specified as being material, or the constituents appear to be fundamentally essential.

In addition, when in the respective embodiments described above, a value such. For example, a number, a number, an amount or an area and the like mentioned in constituent parts of the embodiments does not limit the value to the described value unless the value is clearly specified as being particularly substantial or the value is basically definitive limited.

Moreover, in the respective embodiments described above, when a shape or a relative position and the like of the constituent parts are mentioned, the shape or relative position is not limited to those described unless the shape or relative position is clearly essential is specified or the shape or relative position is basically definitely limited.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• JP 2005-113807 A [0002, 0002]

Claims (6)

Pump comprising: a camshaft ( 14 ), which rotates; a cam ( 15 ) eccentrically disposed with respect to the camshaft, the cam rotating integrally with the camshaft; a cam ring ( 16 ) disposed on an outer circumference of the cam that rotates the camshaft without rotating, the cam ring having a cam ring sliding surface (US Pat. 163 ) includes; a pestle ( 172 ) having a plunger sliding surface ( 173 ) which slides on the cam ring sliding surface in a sliding direction (A) when the cam ring makes its orbital movement, the plunger being disc-shaped and, when the cam ring performs its orbiting motion, extending in a direction perpendicular to the cam ring sliding surface. and moved; a plunger body ( 171 ) formed integrally with the plunger, the plunger body reciprocating with the plunger so as to pump a fluid; a housing ( 11 . 12 ), which encloses the cam ring and the plunger and an opening ( 111 ), wherein the opening ( 111 ) an inner wall ( 112 ) having; and a guided tour ( 30 ), which are inside the opening ( 111 ) and fixed to an outer circumference of the plunger, wherein the guide, along with the plunger, reciprocates along the inner wall of the opening, wherein a range of movement of the guide in the sliding direction is restricted by the inner wall of the opening , A pump according to claim 1, wherein the guide has a wall surface with a guide through-hole (Fig. 301 ) includes. The pump of claim 1, further comprising: a plurality of guide protrusions (10); 302 . 306 ) projecting toward an inner side of the guide, wherein the plurality of guide protrusions is in contact with the plunger. Pump according to one of claims 1 to 3, wherein the plunger and the guide are joined together by press fitting. A pump according to any one of claims 1 to 4, wherein the plunger body and the guide are cylindrical. Pump according to one of claims 1 to 5, wherein the guide, in the sliding direction, is adjacent to the inner wall and a movement of the guide is limited in the sliding direction when the guide contacts the inner wall of the opening.

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