BLOW-OFF VALVE

Abstract

A blow-off valve for controlling the pressure in an intake tract of an internal combustion engine, comprising a housing and a flow path formed in the housing, wherein the flow path is opened and/or closed by means of piston, which may be placed onto valve seat, wherein the piston is connected to a pin, which is moved by means of an electromagnetically producible force, wherein motion of the pin is transferred to the piston, wherein the support of the pin within the blow-off valve is realized by means of exactly one sliding sleeve, wherein the pin is moved in relation to the sliding sleeve.

Claims

1. A blow-off valve for regulating the pressure in an intake section of an internal combustion engine, comprising: a housing; a flow section formed in the housing; a piston moved by means of an electromagnetically producible force; a valve seat, the flow section is opened when the piston is moved away from the valve seat, and the flow section is closed when the piston is seated on the valve seat; a pin connected to the piston such that movement of the pin is transferred to the piston; a sliding sleeve; wherein the bearing of the pin within the blow-off valve is supported by the sliding sleeve, such that the pin is movable relative to the sliding sleeve.

2. The blow-off valve of claim 1, wherein the inner lateral surface of the sliding sleeve follows the outer lateral surface of the pin, such that a fit is created between the sliding sleeve and the pin which enables the pin to slide in the sliding sleeve.

3. The blow-off valve of claim 1, further comprising: a bearing sleeve; wherein the sliding sleeve is received in the bearing sleeve, and the bearing sleeve is arranged in the housing of the blow-off valve.

4. The blow-off valve of claim 3, wherein the sliding sleeve is pressed into the bearing sleeve.

5. The blow-off valve of claim 4, further comprising: a first portion being part of the bearing sleeve, the first portion having a first inner diameter; and a second portion being part of the bearing sleeve, the second portion having a second inner diameter; wherein the first inner diameter is smaller than the second inner diameter.

6. The blow-off valve of claim 5, further comprising: a magnetic element is arranged in the portion having the second inner diameter of the bearing sleeve, such that the magnetic element is inserted into the bearing sleeve after the sliding sleeve is pressed into the bearing sleeve; wherein the magnetic element is spaced from the pin in the radial direction.

7. The blow-off valve of claim 5, further comprising: a first region being part of the sliding sleeve, the first region having a first outer diameter; and a second region being part of the sliding sleeve, the second region having a second outer diameter; wherein the first outer diameter is smaller than the second outer diameter.

8. The blow-off valve of claim 7, wherein the sliding sleeve abuts with the outer surface of the first region against the inner surface of the first portion of the bearing sleeve and the sliding sleeve abuts with the outer surface of the second region against the inner surface of the second portion of the bearing sleeve.

9. The blow-off valve of claim 3, wherein the bearing sleeve is pressed into the housing.

10. The blow-off valve of claim 3, further comprising two contact regions formed between the sliding sleeve and the bearing sleeve, wherein the two contact regions are spaced from one another in the axial direction.

11. The blow-off valve of claim 1, the sliding sleeve further comprising: a plurality of recesses extending along the outer surface of the sliding sleeve in the axial direction; wherein the outer surface of the sliding sleeve is divided into segments which are spaced from one another in the circumferential direction.

12. The blow-off valve if claim 1, wherein the pin is in surface contact with the inner surface of the sliding sleeve, and the pin is arranged at a spacing from the rest of the housing of the blow-off valve.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The invention is explained in detail with the aid of an exemplary embodiment with reference to the drawings. The drawings show:

[0029] FIG. 1 is a sectional view through a blow-off valve, wherein a pin is arranged centrally in the blow-off valve, which pin is connected on one side to a piston and is moved by an electromagnetic force, wherein the pin is supported in a sliding sleeve; and

[0030] FIG. 2 is a perspective view of four elements of the blow-off valve shown in FIG. 1, wherein the sliding sleeve, the bearing sleeve, the pin and the magnetic element are shown in particular.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.

[0032] FIG. 1 shows a blow-off valve 1. The blow-off valve 1 has a housing 2 through which a flow may pass along a flow section. An electromagnet 3 is arranged in the housing 2, which electromagnet 3 is powered by a voltage source (not illustrated) whereby electromagnetic forces are produced, which act on the pin 4 arranged in the blow-off valve 1. The pin 4 is formed in the shape of a rod with a circular cross-section and has a central axial through-bore 6 extending through it in the exemplary embodiment of FIG. 1.

[0033] The pin 4 is guided in a sliding sleeve 5 and may be moved upward and downward relative to the sliding sleeve 5 in a translatory direction. The sliding sleeve 5 is formed as a tubular body and surrounds the pin 4 completely in the circumferential direction.

[0034] The sliding sleeve 5 is received in a bearing sleeve 7, which is in turn received in a suitable opening 8 in the housing 2. The sliding sleeve 5 and the bearing sleeve 7 are pressed together.

[0035] The sliding sleeve 5 has a smaller outer diameter at its upwardly directed end region 9 than at its downwardly directed end region 10. The bearing sleeve 7 has a smaller inner diameter at its upper end region 11 than at its lower end region 12. The sliding sleeve 5 may be introduced into the bearing sleeve 7 from below owing to the differing inner diameter and outer diameter, since an air gap is initially created between the inner surface of the bearing sleeve 7 and the outer surface of the sliding sleeve 5. If, during assembly, the upper end region 9 of the sliding sleeve 5 arrives at the upper end region 11 of the bearing sleeve 7, contact is generated between the sliding sleeve 5 and the bearing sleeve 7. At the same time, contact is generated here between the lower end regions 10 and 12 so that the sliding sleeve 5 ultimately abuts against the bearing sleeve 7 via two contact regions. Between the contact regions, clearances are generated between the sliding sleeve 5 and the bearing sleeve 7.

[0036] A magnetic element 13 is inserted into the bearing sleeve 7 below the sliding sleeve 5. The magnetic element 13 serves primarily for shielding the elements of the blow-off valve 1 below the sliding sleeve 5 from the magnetic field lines produced by the electromagnet 3. The magnetic element 13 is formed as a disk-shaped ring element in FIG. 1.

[0037] A detailed description of the design of the sliding sleeve 5, the bearing sleeve 7, the pin 4 and the magnetic element 13 follows in the description of FIG. 2.

[0038] Through an upward and downward movement of the pin 4, the piston 14 shown in FIG. 1 is moved in opposition to a spring force of the spring element 15. As a result, a flow path through the blow-off valve may be opened or this flow path may be closed.

[0039] FIG. 2 shows four elements of the blow-off valve 1 of FIG. 1. A perspective view of the sliding sleeve 5 is shown on the far left. The sliding sleeve 5 is formed as a tubular body having a central through-bore 20. It is possible to see the region having a larger outer diameter 21 and the region 22 having an outer diameter which is smaller than that of the region 21. Extending in the circumferential direction, the sliding sleeve 5 has four recesses 23, which are arranged spaced from one another through 90 degrees in the circumferential direction and extend over the entire length of the sliding sleeve 5 in the axial direction. With the inner surface of the bearing sleeve 7, these recesses form channels through which it is possible to achieve a pressure equalization between the cavities above the sliding sleeve 5 and below the sliding sleeve 5.

[0040] Shown next to this on the right is the bearing sleeve 7, which likewise corresponds to a tubular body. It is possible to see, in particular, the portion 24 having a smaller inner diameter and the portion 25 having a larger inner diameter. As could already be seen in FIG. 1, the bearing sleeve has a substantially constant wall thickness in the axial direction. The bearing sleeve 7 in FIG. 2 is shown in the same alignment as in FIG. 1. The sliding sleeve 5, on the other hand, is shown rotated through approximately 180 degrees.

[0041] The pin 4, which has a central through-bore extending in the axial direction, is shown as the second element from the right. This bore may likewise serve for the pressure equalization above and below the sliding sleeve 5. The outer dimensions of the pin 4 are selected such that the pin 4 may slide along the inner surfaces of the sliding sleeve 5. To this end, the sliding sleeve 5 also has, in particular, a constant inner diameter.

[0042] The magnetic element 13, which is formed as a disk-shaped ring element, is shown on the far right. The magnetic element has, at least on its upwardly directed edge extending along the outer circumference, a sloping chamfer 26 which, in particular, facilitates the insertion into the bearing sleeve 7. The magnetic element 13 is dimensioned such that it may be trapped with respect to the inner wall of the bearing sleeve 7. The bore 27 through the magnetic element 13 is dimensioned such that the pin 4 is guided freely and without contact through the bore 27.

[0043] FIGS. 1 and 2 show, in particular, a specific construction of a blow-off valve 1 and, in particular, the bearing of the pin 4 within the housing 2. It is also possible to provide alternative structural designs of the bearing sleeve 7, the sliding sleeve 5 and the pin 4 within the scope of the invention, such that the feature of the bearing of the pin 4 is realized by only one bearing point in the form of a sliding sleeve.

[0044] In particular, the exemplary embodiment of FIGS. 1 and 2 is not restrictive in nature and serves to illustrate the inventive idea.

[0045] The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.