JP2014530316A - Plunger structure group for fuel high pressure pump and fuel high pressure pump - Google Patents

Abstract

The present invention relates to a plunger structure group for a fuel high-pressure pump for supporting a pump plunger (1) capable of stroke movement of a pump element on a cam (2) of a drive shaft (3), and comprising a notch (5). And a support element (4) having a roller (6) rotatably supported in the notch (5). According to the invention, in order to hold the roller (6) in the notch (5) of the support element (4), a holding element (7) is further provided, the holding element (7) It is coupled to the support element (4) in a shape coupling manner, whereby the holding element (7) is prevented from rotating relative to the longitudinal axis A of the pump plunger (1). [Selection] Figure 2

Description

  The invention relates to a group of plunger structures for a fuel high-pressure pump having the features of the preamble of claim 1. Furthermore, the present invention relates to a fuel high-pressure pump having such a plunger structure group.

  The plunger structure group of the said type is described in patent document 1, for example. This known plunger structure group has a hollow cylindrical plunger body, and a roller shoe for rotatably supporting a roller is accommodated in the plunger body. Since the pump plunger of the pump element can be supported by the cam of the drive shaft via the roller, when the drive shaft rotates, the pump plunger is driven to perform a stroke motion. Since the return spring is supported by a spring receiver that is shape-coupled to the pump plunger, the reset of the pump plunger is guaranteed. The shape connection is obtained by engaging the spring receiver from behind with the plunger foot of the pump plunger.

  In order to prevent the rotation of the roller around the longitudinal axis of the pump plunger during driving of the high-pressure pump, according to Patent Document 1, one end of the return spring can be coupled to the roller shoe in a shape coupling manner. Proposed. By preventing such rotation, a uniform load on the roller is obtained, and wear is reduced.

German Patent Publication No. 102008000699

  Not only the rollers are subject to wear, but the surfaces of the other components of the plunger structure group that are in frictional contact with the rollers are also subject to wear. Accordingly, an object of the present invention is to provide a plunger structure group having high wear resistance.

  This problem is solved by a plunger structure group having the features of claim 1 and a fuel high-pressure pump having the features of claim 7. Preferred embodiments of the invention are described in the dependent claims.

  The proposed plunger structure group has a support element with a notch, in which a roller is rotatably supported. According to the present invention, a holding element is further provided for holding the roller in the notch of the support element, and the holding element is coupled to the support element in a shape coupling manner. Thereby, rotation prevention of the holding element with respect to the longitudinal axis A of the pump plunger is obtained.

  In general, the roller shoe has a supporting function and a holding function because the winding angle of the notch for rotatably supporting the roller is> 180 °. In order to fit the roller into the roller shoe, the roller is pushed in from the side. When the roller shoe is fitted into the hollow cylindrical plunger body, the roller is securely accommodated in the roller shoe, and at this time, the circular top portion of the roller abuts against the inner wall of the plunger body. The inner wall of the plunger body thus forms an axial sliding surface for the roller.

  In contrast, in the group of plunger structures according to the invention, the support and holding functions of the rollers are distributed between two components: the support element and the holding element. Accordingly, the wrap angle of the support element notch may be selected to be <180 °. Removal of the roller from the notch in the support element is prevented by the holding element. The holding element has a notch for partially accommodating the roller, the width of the notch being chosen to be smaller than the diameter of the roller at least at one location. In a preferred manner, the cross section of the notch is adapted to the cross section of the roller.

  In order to prevent the roller from tilting by rotating the holding element relative to the support element during operation of the high-pressure pump, the holding element is connected to the support element in a shape-coupled manner.

  As long as the axial sliding surface for the roller is formed by the support element and / or the holding element, the sleeve-like plunger body can be omitted. Accordingly, the roller abuts against the partition surface of the support element and / or the holding element with its circular top. Thus, all surfaces that are dynamically loaded via the rolling movement of the rollers are formed in the support element and / or the holding element, and correspondingly these surfaces are manufactured from a wear-resistant material and / or Or it may be provided with a wear resistant coating. Omitting the plunger body eliminates the need to push the support element into the plunger body. The risk is eliminated by omitting the plunger body, as there is a risk of deformation of the support element as well as the notch formed in the support element to accommodate the roller during pushing. This has an advantageous effect on the running characteristics of the roller and thus on the wear. Moreover, by omitting the plunger body, the weight of the plunger structure group can be reduced, which has proved advantageous as well. This is because when the plunger structure group is used in a fuel high pressure pump, the return spring can be designed smaller on the one hand, and on the other hand, the distance between the camshaft and the cylinder head upper side is reduced based on the weight reduction. Because it is done. Therefore, the weight of the cylinder head or the pump housing can be further reduced.

  In order to produce a shape connection between the holding element and the support element, according to a preferred embodiment of the invention, the holding element is at least partially fitted in the support element. Furthermore, alternatively or additionally, the support element may have at least one axial addition that engages the holding element. The shape connection must prevent the holding element from rotating relative to the support element about the longitudinal axis of the pump plunger.

  As a means according to another embodiment, it is proposed that the axial additional part is formed in an arc shape and surrounds a partial outer peripheral region of the holding element. In this case, the additional portion in the axial direction is not necessarily installed on the support element, and may be formed by cutting. In order to produce a plurality of arc-shaped additional portions, the support element may be first cut into a circular shape, for example, and this cutting portion may be connected to the outer peripheral surface via a plurality of grooves extending in the radial direction. These grooves cooperate with the projections of the holding elements, which are configured corresponding to these grooves, so that a shape connection is obtained.

  More preferably, the holding element is pushed into the support element. Thereby, when the shape coupling between the holding element and the support element is used only as a rotation preventing means, the holding element is secured so as not to fall off.

  In a preferred manner, the holding element forms an axial sliding surface for the roller. Therefore, the position of the roller is ensured exclusively by the holding element. Therefore, the winding angle of the roller is significantly smaller than 180 °, and may be 140 °, for example.

  According to another embodiment of the invention, it is proposed that the roller has a flat circular top surface, with which the roller abuts the holding element and / or the support element. Much higher lateral thrust forces can be absorbed by surface contact rather than the general type of point contact. This further reduces wear. Moreover, a roller having a flat top can be easily and inexpensively manufactured.

  Further, in the fuel high-pressure pump provided with the plunger structure group according to the present invention that has been further proposed to solve the problem at the beginning, the support element of the plunger structure group is directly inserted into the housing hole of the fuel high-pressure pump. It is characterized by. Thus, the support element is not housed in a hollow cylindrical plunger. The advantages of omitting the plunger body have already been described and reference is made to that description.

  Further, it has been proposed that the holding element has a protrusion protruding radially with respect to the support element, the protrusion cooperating with a groove in the housing hole to prevent the plunger structure group from rotating. .

  Preferably, the plunger structure group is coupled to the pump plunger via a spring receiver, and the spring receiver is pressure-bonded to the pump plunger. This allows the pump plunger to be configured without a plunger foot, thereby simplifying manufacture.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

It is the perspective view which fractured | ruptured partially the area | region of the plunger structure group of a well-known high pressure pump. It is a longitudinal cross-sectional view of the plunger structure group by this invention. It is the figure which looked at the plunger structure group shown in FIG. 2 from the bottom. FIG. 4 is a longitudinal sectional view of the support element, holding element, and roller of the plunger structure group shown in FIGS. 2 and 3, in which the cutting plane is shifted by 90 ° with respect to the cutting plane of FIG. 2.

  The high-pressure pump in the region of the plunger structure shown in part in FIG. 1 has at least one pump element with a pump plunger 1 guided for stroke movement, said pump plunger 1 being The cam 2 of the drive shaft 3 is supported by a plunger structure group. The plunger structure group is accommodated in the housing hole 11 of the housing portion 20 of the high-pressure pump so as to be slidable in the axial direction.

  The illustrated plunger structure group includes a sleeve-like plunger body 13 and a support element 4 accommodated in the plunger body 13, and the support element 4 is a notch for rotatably supporting the roller 6. 5 The plunger structure group is directly supported on the outer peripheral surface of the cam 2 of the drive shaft 3 via the roller 6. The return spring 14 reliably brings the plunger structure group into contact with the cam 2.

  The support element 4 and the return spring 14 of the plunger structure group are respectively supported on opposite sides of the annular collar 16 of the plunger body 13. In this case, the return spring 14 is indirectly connected to the annular collar 16 via the spring receiver 12. It is supported by. The spring receiver 12 is used to connect the plunger structure group and the pump plunger 1. For this purpose, the spring receiver 12 has a central notch, and the pump plunger 1 is guided through the central notch so that the spring receiver 12 is engaged with the plunger foot 15 of the pump plunger 1 from behind. To do. In this manner, a shape coupling (constraint by shape) type coupling between the pump plunger 1 and the plunger structure group is obtained.

  The plunger structure group according to the present invention shown in FIGS. 2 to 4 is different from that of FIG. 1 in that the plunger body 13 is not provided. The support element 4 is directly accommodated in the housing hole 11 of the housing part 20 of the high-pressure pump (see FIG. 2). The support element 4 has a central cutting recess, and the cutting recess extends beyond the groove 18 to the outer periphery of the support element 4 (see FIG. 3). The cutting recess is defined by two arcuate addition portions 8, which are formed rotationally symmetrically and separated from each other by grooves 18. A holding element 7 is pushed into the central cutting recess, which holding element 7 has a projection 17 which engages in a groove 18, thereby obtaining a shape connection (FIG. 3). And FIG. 4). Accordingly, the protrusion engaging with the groove 18 prevents the holding element 7 from rotating about the longitudinal axis A of the pump plunger 1 relative to the support element 4.

  The protrusion 17 protrudes beyond the outer peripheral surface of the support element 4 in the radial direction (see FIG. 4), and is used to prevent rotation of the plunger structure group in the housing hole 11. For this purpose, a groove (not shown) that cooperates with the protrusion 17 is formed in the housing hole 11.

  Further, as shown in FIG. 4, the roller 6 has a flat top surface 10, that is, a flat end surface, with which the roller 6 is formed by a holding element 7. It contacts the sliding surface 9 in the axial direction (see FIGS. 3 and 4).

  Furthermore, according to FIG. 2, the support element 4, the holding element 7 and the spring receiver 12 have a plurality of flow-through openings 19, which are arranged on the sides of the roller 6 (see FIG. 2). (See also 3). Through these flow-through openings 19, fuel flow is ensured.

  Furthermore, the pump plunger 1 is shown without the plunger foot 15, so that the spring receiver 12 is pressed against the pump plunger 1. However, this is not always necessary. The pump plunger 1 may include a plunger foot 15. The end of the pump plunger 1 opposite to the spring receiver 12 is accommodated in the cylinder head 21 of the high-pressure pump.

DESCRIPTION OF SYMBOLS 1 Pump plunger 2 Cam 3 Drive shaft 4 Support element 5 Notch 6 Roller 7 Holding element 8 Additional part 9 Sliding surface 10 Round top surface 11 Housing hole 12 Spring holder 13 Plunger body 14 Return spring 15 Plunger foot 16 Ring collar 17 Protrusion 18 Groove 19 Through-flow opening 20 Housing part A Vertical axis

Claims (9)

A plunger structure group for a fuel high-pressure pump for supporting a pump plunger (1) capable of stroke movement of the pump element on a cam (2) of a drive shaft (3), the support element having a notch (5) ( 4), wherein the roller (6) is rotatably supported in the notch (5),
In order to hold the roller (6) in the notch (5) of the support element (4), a holding element (7) is further provided, the holding element (7) being the support element (4). For the high-pressure fuel pump, characterized in that the holding element (7) is prevented from rotating relative to the longitudinal axis (A) of the pump plunger (1). Plunger structure group.   In order to obtain the shape coupling, the holding element (7) is at least partially fitted in the support element (4) and / or the support element (4) is connected to the holding element (7). 2. Plunger structure group according to claim 1, characterized in that it has at least one axial addition (8) to engage.   3. The plunger structure group according to claim 2, wherein the axial addition portion (8) is formed in an arc shape and surrounds a partial outer peripheral region of the holding element (7).   4. Plunger structure group according to any one of claims 1 to 3, characterized in that the holding element (7) is pushed into the support element (4).   5. Plunger according to any one of claims 1 to 4, characterized in that the holding element (7) forms an axial sliding surface (9) for the roller (6). Structure group.   Said roller (6) has a flat circular top surface (10), by means of which said roller (6) has said holding element (7) and / or said support element ( The plunger structure group according to any one of claims 1 to 5, wherein the plunger structure group abuts on 4). The fuel high-pressure pump having the plunger structure group according to any one of claims 1 to 6,
A high-pressure fuel pump, wherein the support element (4) is inserted directly into the housing hole (11) of the high-pressure fuel pump.   The holding element (7) has a protrusion (17) protruding radially with respect to the support element (4), and the protrusion (17) cooperates with a groove in the housing hole (11). The fuel high-pressure pump according to claim 7, wherein the plunger structure group is prevented from rotating.   The plunger structure group is coupled to the pump plunger (1) via a spring receiver (12), and the spring receiver (12) is pressure-bonded to the pump plunger (1). Item 9. The fuel high-pressure pump according to Item 7 or 8.

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